Is it Safe to Take Supplements if You Have Diabetes?

You will find supplements for anything and everything these days. Even when you do not suffer from an ailment, supplements are suggested to keep you healthy and ailment-free. According to CDC, use of supplements is common among US adult population – over 50% adults used supplements during 2003-2006, with multivitamins/multiminerals being the most commonly used.

So when you are a diabetic, especially if you have prediabetes and type-2 diabetes, you may find yourself confronting a large number of options for supplements that claim to support, reduce and even cure your diabetes. Diabetes is quite a frustrating disorder and you may find yourself tempted to try out these supplements one after another. But is it really safe to take supplements when you are a diabetic? Let us find out. But before that you need to understand what exactly supplements are.

Defining Supplements

As the name suggests, a supplement is anything that adds on to something. A dietary supplement is therefore something that one takes in addition to one’s diet to get proper nutrition. US Congress in the Dietary Supplement Health and Education Act defines dietary supplements as having the following characteristics:

1. It is a product that is intended to supplement the diet;
2. It contains one or more dietary ingredients (including vitamins, minerals, herbs and other botanicals, amino acids, and other substances) or their constituents;
3. It is intended to be taken by mouth as a pill, capsule, tablet, or liquid;
4. It is not represented for use as a conventional food or as sole item of a mean or a diet; and,
5. It is labeled on the front panel as being a dietary supplement.

Now let us look at some general benefits and risks of taking supplements. We will discuss these in context of diabetes later in the article.

Benefits and risks of taking supplements

Supplements may help you get adequate amounts of important nutrients in case your food is unable to provide these, but these supplements cannot replace a varied diet which is important for a healthy life. According to the Office of Dietary Supplements (ODS) at the National Institute of Health (NIH), scientific evidence has showed that some supplements can be beneficial in maintaining overall health and for managing some health conditions like calcium and vitamin D supplements for bone health and for preventing bone loss, and fish oil that provides omega-3 fatty acids may help people with heart disease.

Having said this, supplements may contain active ingredients and these may have a strong effect on the body in terms of unexpected side-effects. Another thing to be wary of is that supplements are not medicines, so one cannot really replace the medicine with supplements. Some supplements may interact with your prescription medicines and give you really bad side-effects – they may reduce the effect of your medicines, they can break-down your medicine, or they may even produce some combinatorial effects with your medicine to produce unexpected side effects. Some may increase bleeding and should therefore also be stopped if you are about to have a surgery or take blood thinning medications.

ODS also warns that more may not always be better – if you take some supplements in excess they may cause you more damage than benefit. It is therefore important that you are not overdosing yourself with supplements. As a majority of supplements are not tested in pregnant women, nursing mothers, or children, you should be extra cautious with supplements if you are pregnant, nursing, or are considering giving these to your children.

With this background, let us proceed to the supplements for diabetics, their benefits and risks and how you can make the most with these.

Diabetes and supplements

Following are some of the supplements that are popular in the diabetic community. Let us see what science says about these supplements, how they work (if they do), and how safe these are:

Vitamins: While type 2 diabetes is a disorder linked largely to carbohydrate and fat metabolism, its complex and multifactorial nature also lead to involvement of certain vitamins (or lack of these) in some way. Some vitamins have antioxidant function. Oxidative stress is a result of waste products called free-radicals that are created when body turns food into energy. Diabetes is a disorder where there is a lot of cell damage due to oxidative processes leading to diabetic complications and therefore an antioxidant therapy sounds sensible. Other vitamins are important due to other effects. Let us find out which vitamins have been linked with diabetes and could be recommended.

• Vitamin A: Vitamin A is made up of various but similar components: retinol is the most active form and is present in animal tissues while carotenes are present in vegetable tissues which are converted into retinol when we eat them. A protein that transports retinol, called as the retinol binding protein (RBP), has been found to have an effect on insulin sensitivity. Type 2 diabetics who are very old have been shown to have lower levels of vitamin A. Another study showed that levels of beta-carotene in the blood of diabetics were significantly lower than in non-diabetics, although their retinol concentrations were normal. This study also found that levels of RBP in the blood and urine were much higher in diabetics than in non-diabetics – this makes sense because the body will produce more of this transporter protein in case of vitamin A deficiency to make sure it is able to capture all the available vitamin. Another controlled study showed that higher levels of beta-carotene in the blood reduced the risk of developing type 2 diabetes, but if the patients had cardiovascular risk factors like obesity, smoking, cholesterol and high blood pressure, beta carotene could not reduce the risk for developing diabetes.
  • Side-effects and Precautions: Too much vitamin A in the form of supplements can have side-effects like dizziness, nausea, headaches, coma and even death. It can also cause birth defects in babies if the pregnant mother takes too much of vitamin A supplements.
  • Interactions with drugs: Vitamin A can potentially interact with prescription or non-prescription drugs that you take. Some drugs can lower your absorption of vitamin A while others can lead you to have dangerously high levels of vitamin A in your blood. It is therefore in your best interest to talk to your doctor about it before you start with vitamin A supplements.
• Vitamin B: Thiamine (B1), Riboflavin(B2), Niacin(B3), Pantothenic acid(B5), Pyridoxine(B6), Biotin(B7, also called Vitamin H), Folic acid (B9), and Cobalamine (B12) are grouped as Vitamin B.
  • B1: Low levels of B1 and increased clearance by the kidneys has been observed in both type 1 and type 2 diabetics. One month supplementation with B1 was also found to decrease blood glucose and leptin(the appetite hormone) levels. This vitamin may therefore be useful for diabetics.
    • Side-effects and Precautions: Vitamin B1 supplementation should not be overdone as this may actually increase the risk of developing diabetic complications.
    • Interactions with drugs: Some drugs (for example, Furosemide commonly known as Lasix used to treat blood pressure and fluid accumulation; Fluorouracil used in chemotherapy) can lower the levels of vitamin B1 in your body. Always talk to your doctor before deciding to take this supplement in case you are taking any other medicines.
  • B2: There is not much information available regarding the effect of this vitamin on diabetes.
  • B3: Not much research has been done on the relation of this vitamin with diabetes. However, there are studies that show that supplementation with B3 may increase HDL(good)-cholesterol, reduce LDL(bad)-cholesterol and triglycerides. In this way it may be helpful to diabetics as most diabetics also have issues with their cholesterol. However, there are also studies that show that B3 supplementation may slightly increase the risk for those who already have prediabetes to develop type 2 diabetes and that overdoing supplementation with vitamins such as B1, B2, and B3 may increase oxidative stress and insulin resistance thereby increasing the risk of diabetic complications.
  • B5: There is not much information available regarding the effect of this vitamin on diabetes.
  • B6: As to B6, lower levels of active form of this vitamin(pyridoxal-5’-phosphate or PLP) has been found in newly diagnosed diabetics as compared to non-diabetics. Although a direct correlation between B6 status and diabetes is not clear, there is evidence that its deficiency may help in the progression of some of the complications of diabetes. A study where 10 type 2 diabetics with mild to moderate diabetic retinopathy (retinal damage) were supplemented with B6 for 6 months showed a decrease in swelling of the retina and increase in light sensitivity.
    • Side-effects and Precautions: Taking high doses of vitamin B6 supplements for a year or longer can result in severe nerve damage. Other side effects of excess vitamin B6 supplementation include painful and unsightly patches on the skin, extreme sensitivity to sunlight, nausea and heartburn.
    • Interaction with drugs: There can be interactions of this vitamin with any other drug that you might be taking. It is therefore recommended that you discuss with your doctor prior to taking this vitamin. Examples of interactions – when taken with cyclosporine that is used to treat tuberculosis, it could worsen any seizures or nerve damage that the drug might cause; some epilepsy drugs can reduce B6 levels and B6 can also reduce the ability of the drug to control seizures.
  • B7: It is very rare for anyone to have biotin (B7) deficiency. However, it is possible that excessive deficiency of this vitamin causes abnormality in regulation of glucose. Back in 1993, a Japanese study reported lower levels of biotin in 43 patients with type 2 diabetes when compared to 64 non-diabetics. When the researchers gave daily supplement of 9mg of biotin for 1 month to 28 type 2 diabetics, there was an average decrease of 45% in the fasting blood glucose levels. However, another 2004 study found no such reduction in blood glucose levels on supplementation with biotin. A study that combined biotin and chromium to study their effect on diabetes is often cited to support the use of biotin in reducing blood glucose and lipid levels, chromium by itself has been shown to have this effect (please read more on chromium below) – so it is not really correct to say for sure that biotin has this effect. In light of this contradictory data, there isn’t sufficient evidence to suggest that B7 can really improve blood glucose or lipid levels in diabetics.
  • B9: In relation to type 2 diabetes, vitamin B9 deficiency seems to be associated with vitamin B12 deficiency. Deficiency of vitamin B9 and B12 are linked with increase of homocysteine in the blood and increased homocysteine levels are linked to type 2 diabetes and its complications like diabetic retinopathy. Studies have also found that damage to DNA and to the cells due to type 2 diabetes can be decreased through B9 supplementation. B9 supplementation is also found to improve blood sugar control in type 2 diabetes as it helps reduce the HbA1C, fasting blood glucose, serum insulin, insulin resistance and homocysteine levels. Patients taking metformin to control their blood sugar should note that metformin can by itself cause a deficiency of B9. A research showed that supplementing diabetic men who were on metformin for 8 weeks with B9 showed reduction in their homocysteine levels and improvement in antioxidant capacity.
    • Side-effects and Precautions: Taking too much B9 can hide any deficiency in vitamin B12. Vitamin B12 deficiency can cause nerve damage and can lead to permanent damage to the brain, spinal cord and nerves if not detected. Large doses of this vitamin can also cause cancers like colorectal cancer in some people.
    • Interactions with drugs: As with other vitamins, B9 can also interact with other drugs and cause harm, which is why you must consult your doctor before starting with B9 supplementation, especially if you are taking any other medicines. For example, it can interact with methotrexate that is used to treat cancer; certain medicines for epilepsy can cause low levels of this vitamin in the blood and, conversely, this vitamin can reduce the levels of these drugs in the blood.
  • B12: Like for vitamin B9, B12 deficiency can be caused by taking metformin. B12 deficiency is also found in diabetic patients not on metformin. Research has shown that nerve damage due to diabetes is worse in patients who have vitamin B12 deficiency. Supplementation with vitamin B12 has been found to improve the symptoms in patients with severe diabetic neuropathy.
    • Side-effects and precautions: Vitamin B12 has not been found to cause any harm or side-effects. However, as with everything, you should avoid taking very high doses of vitamin B12.
    • Interaction with drugs: Several medicines can reduce your absorption of vitamin B12, for example, metformin (for diabetes), the antibiotic chloramphenicol, or medicines like omeprazole and ranitidine (used to treat peptic ulcers). Please consult your doctor before starting B12 supplementation.
• Vitamin C: People with type 2 diabetes have high levels of oxidative stress due to high blood sugar levels and therefore require more vitamin C which is a potent antioxidant. Vitamin C concentrations have been found to be low in diabetics. Higher vitamin C concentrations are linked to reduced levels of HbA1C and blood glucose. Diabetes also leads to teeth and gum disease where vitamin C supplementation along with dental procedures (scaling and root planing) has been found to improve chronic teeth and gum disease in newly diagnosed type 2 diabetics. A controlled research has also showed that vitamin C supplementation for 3 months resulted in lowered blood pressure, blood glucose levels and an increase in antioxidative enzymes.
  • Side-effects and Precautions: Too much vitamin C can cause side-effects like diarrhea, nausea and stomach cramps. People who have hemochromatosis, due to which their bodies store excess iron, should be extra cautious taking this vitamin as it can worsen iron overload.
  • Interaction with drugs: Vitamin C supplements may have undesirable interactions with cancer treatments – there is a possibility that vitamin C may protect the tumor cells against cancer therapy, however the evidence is not very strong. If you are taking any form of cancer therapy, it is recommended that you talk to your doctor before taking this or any other antioxidant type supplements. There is also some evidence that vitamin C along with other antioxidant supplements reduced the heart-protecting function of statin-niacin combination used for controlling cholesterol levels.
• Vitamin D: There is evidence from a Finnish study that vitamin D may be important in changing the risk of diabetes. There is also suggested (but not proven) association between vitamin D and type 2 diabetes – the effect of lack of vitamin D on pancreatic beta cell dysfunction, impaired insulin action and inflammation in the body. Some cohort studies, like one Australian study, have also showed an association between low vitamin D levels and the risk of developing type 2 diabetes. As to supplementation with vitamin D, the research is not in agreement – while some show usefulness of vitamin D supplements in improving diabetes and diabetic complications, others have not been able to find any effect!
  • Side-effects and Precautions: Vitamin D toxicity may happen if you take too much vitamin D. This can cause nausea, vomiting, lack of appetite, constipation, weakness and weight loss. Vitamin D in high doses can also raise the blood levels of calcium causing confusion, disorientation, and problems with heart beat. Too much vitamin D can also damage kidneys. Please note that vitamin D poisoning only happens with vitamin D supplements, not with vitamin D from sunshine as our body can limit the amount of vitamin D it produces from sunshine.
  • Interaction with drugs: Vitamin D supplements can interact with other medicines, so you should be cautious taking this supplement if you are taking other medicines. It is worthwhile talking to your doctor about it in such a case. Here are some examples: Vitamin D may affect blood pressure and so you should be careful if you are taking blood pressure controlling medicines; Estrogen (used in hormone replacement therapy) and Isoniazid (tuberculosis treatment) increase blood vitamin D levels.
• Vitamin E: Vitamin E is an antioxidant as well and is therefore required in higher levels by diabetics. Vitamin E concentrations have been found to be low in diabetics. A controlled research has also showed that vitamin E supplementation for 3 months resulted in lowered blood pressure, blood glucose levels and an increase in antioxidative enzymes. However, there are other studies that did not find any effect of vitamin E supplementation on insulin sensitivity and blood glucose levels. Although there are recent studies that imply a role of vitamin E in controlling diabetes and its complications, the authors suggest that the effect needs to be studied in a large number of patients and over a long period of time to be able to say for sure that vitamin E supplementation indeed can modify diabetic parameters.
  • Side-effects and Precautions: High doses of vitamin E in supplement form may increase the risk of bleeding as it decreases the body’s ability to form blood clots after an injury. There may be an increased risk of developing prostate cancer if you take very high doses of vitamin E.
  • Interaction with drugs: Vitamin E will supplement the effect of anticoagulant medicine (blood thinning medicine) and cause increased risk of bleeding. Like other antioxidant vitamins, vitamin E will also reduce the heart-protective effects of statin-niacin combination which is taken to reduce blood cholesterol levels. It also may reduce the effectiveness of cancer treatment by protecting the tumor cells against the treatment. It is therefore important that you talk to your doctor if you are taking any other treatment or medication before you start taking vitamin E.
• Vitamin K: Vitamin K complex is made up of phylloquinone and menaquinone. Several studies have showed that there is an association of vitamin k levels with insulin sensitivity and metabolism of glucose. Thus, there seems to be an association of vitamin K with diabetes. In 2010, a Dutch study was conducted on 38094 people and was followed up for 10.3 years. This study found that those who had good levels of either phyloquinone or menaquinone had a reduced risk of developing type 2 diabetes. Similarly, a 2012 detailed and long term study from Spain was conducted on 1069 people without diabetes who were already taking part in the Prevention with the Mediterranean Diet trial. Every year data was collected to check for diabetes. After one year, people with higher levels of vitamin K were found to have lower risk for diabetes. Vitamin K has more long-term studies on a large number of people showing an impact on whether or not a person develops type 2 diabetes. It therefore has more evidence and can be recommended to everyone who has a known risk for getting type 2 diabetes.
  • Side-effects and Precautions: Vitamin K does not have any known side-effects. People with Glucose-6-phosphate dehydrogenase (G6PD deficiency) should not take vitamin K.
  • Interaction with drugs: Vitamin K blocks the effects of blood thinning medications. Please talk to your doctor if you are taking any medications before starting this supplement.
• Dosage of different vitamins: The following table taken from the USDA website outlines the daily recommended intake (RDI) and Adequate Intake (AI) of the different vitamins for healthy people.
• RDI: recommended dosage for 97-98% people (sufficient scientific evidence)
• AI: recommended dosage but it is not sure how many people the dose may be valid for (Insufficient scientific evidence). AI is marked with a * here.
• UL: highest level of daily intake that is likely to not pose any risk of bad health effects in almost the whole of the population. UL are provided in parantheses in RED. ND= not determined due to lack of sufficient data. In such cases you should be extra careful in going above the RDI/AI. Please note: a) this is total of what you get through food, water, and supplements, b) UL may not be valid for people with diabetes – your doctor may ask you to go below the RDI or above the UL depending on your condition; please listen to your doctor. Even healthy people should generally stick to the RDI and not go regularly towards UI.

	Children (1 to 8y)	Males (9 to >70y)	Females (9 to >70y)	Pregnancy (14 to 50y)	Lactation (14 to 50y)
Vit A (mcg/day)	300-400 (600-900)	600-900 (1700-3000)	600-700 (1700-3000)	750-770 (2800-3000)	1200-1300 (2800-3000)
Vit B1 (mg/day)	0.5-0.6 (ND)	0.9-1.2 (ND)	0.9-1.1 (ND)	1.4 (ND)	1.4 (ND)
Vit B2 (mg/day)	0.5-0.6 (ND)	0.9-1.3 (ND)	0.9-1.1 (ND)	1.4 (ND)	1.6 (ND)
Vit B3 (mg/day)	6-8 (ND)	12-16 (ND)	12-14 (ND)	18 (ND)	17 (ND)
Vit B5 (mg/day)*	2-3 (ND)	4-5 (ND)	4-5 (ND)	6 (ND)	7 (ND)
Vit B6 (mg/day)	0.5-0.6 (30-40)	1-1.7 (60-100)	1-1.5 (60-100)	1.9 (80-100)	2 (80-100)
Vit B7 (mcg/day)*	8-12 (ND)	20-30 (ND)	20-30 (ND)	6 (ND)	7 (ND)
Vit B9 (mcg/day)	150-200 (300-400)	300-400 (600-1000)	300-400 (600-1000)	600 (800-1000)	500 (800-1000)
Vit B12 (mcg/day)	0.9-1.2 (ND)	1.8-2.4 (ND)	1.8-2.4 (ND)	2.6 (ND)	2.8 (ND)
Vit C (mg/day)	15-25 (400-650)	45-90 (1200-2000)	45-75 (1200-2000)	80-85 (1800-2000)	115-120 (1200-2000)
Vit D (mcg/day)	15 (63-75)	15-20 (100)	15-20 (100)	15 (100)	15 (100)
Vit E (mg/day)	6-7 (200-300)	11-15 (600-1000)	11-15 (600-1000)	15 (800-1000)	19 (800-1000)
Vit K (mcg/day)*	30-55 (ND)	60-120 (ND)	60-90 (ND)	75-90 (ND)	75-90 (ND)

Minerals/Elements: As there is a change in the metabolism in diabetics in addition to increased loss of fluids due to excessive urination and sweating, there is an increased loss of minerals in the urine leading to reduced levels of these essential micronutrients in the blood. Let us find out what sort of scientific evidence exists about the role of these in diabetes and its complications.

• Chromium: Chromium is a mineral that is required by our bodies in very tiny (trace) amounts. Chromium is naturally found in many foods, but if you have chromium deficiency your body will not be able to use glucose efficiently as chromium enhances the action of insulin. This is the reason why chromium supplementation has been thought to be able to help diabetics in lowering their blood glucose. However, research done up to 2007 was unable to clearly show any beneficial effect of chromium on diabetes.
  • A small study on 11 patients with type 2 diabetes who were on insulin was done by Mainz and colleagues from Czech Republic in 2014. They gave chromium supplementation to these patients and studied levels of fasting blood sugar and HbA1c. They found that there was a significant reduction in fasting blood glucose and HbA1c. They also found that 8 weeks after the supplementation was stopped, the fasting blood sugar and HbA1C both returned to the previous higher values. Based on this work, Mainz and colleagues suggested that more and larger studies be done on this mineral and its effect on diabetes as it did seem to have some potential in reducing insulin resistance.
  • Paiva and colleagues from Brazil, in 2015, published their results from a controlled study on 71 people with type 2 diabetes – 39 of these were given placebo (tablets without any chromium) and 32 were given chromium supplementation. They found a significant reduction in fasting blood sugar levels and blood sugar levels after meals. The researchers however mention that long term effects of chromium supplementation should be studied.
  • Another research by McIver and colleagues from USA published in 2015 analysed information of supplement usage by over 28000 people in the US. They found that the odds of having type 2 diabetes was lower in people who took chromium containing supplements in the 30 days prior to the study.
  • Analysis of 13 controlled studies on effect of chromium supplementation on diabetics and those with high risk for developing diabetes was published in 2016 by Mauro-Martin and colleagues from Spain. They found a significant effect of chromium in reducing fasting blood sugar and on total cholesterol levels.
  • Side-effects and Precautions: Chromium from food source is considered safe. In contrast, excess supplementation may work against helping diabetes – it can reduce the effect of insulin. This is a common thing with trace minerals – the minerals that our body needs in very minute amounts. Our intestines do not absorb chromium too much as our bodies don’t need large amounts and most of it gets removed from the body in urine. Too much chromium can cause stomach irritation, itching and flushing. According to University of Maryland Medical Center, there are also reports of fast, irregular heartbeats, liver problems and kidney damage resulting from too much chromium supplementation. Also, people with chromate or leather contact allergies may be allergic to chromium.
  • Interactions with drugs: Some drugs – for example, antacids, corticosteroids – may lower the absorption of chromium by intestines by changing the acidity of the stomach. Other medications like beta-blockers, insulin, nicotinic acid, nonsteroidal anti-inflammatory drugs, and pain-killers like ibuprofen, naproxen, or aspirin can increase the absorption of chromium. Conversely, chromium can also increase the effect of these drugs. You must therefore be careful when taking chromium with any medicines and contact your doctor for advice before starting on chromium. If you are taking insulin or blood glucose lowering medicines you should be aware that taking chromium may cause hypoglycemia – so always take it under guidance of your doctor.
  • Dosage: Chromium supplements are available typically in the range of 50-200mcg. It is not clear which of the many available forms of chromium is the best to take as there is limited data on how they are absorbed by our intestines. Take chromium only after consultation with your doctor. Never go above the daily dose of 200mcg. Due to insufficient evidence RDI could not be established. The AIs are shown in the table at the end of this section. The data is taken from the website of NIH Office of Dietary Supplements.
• Selenium: It is generally said that selenium in some ways behaves like insulin (is an insulin-mimetic). However, the association between blood selenium levels and type 2 diabetes is considered controversial due to conflicting reports. Wang and colleagues from China recently analyzed 5 studies with a total of over 13000 patients involved to investigate the association between type 2 diabetes and selenium. They found that in populations both with relatively low (97.5mcg/L) selenium in blood and in those with relatively high (>132.5mcg/L) selenium in blood, type 2 diabetes was common. This makes sense as selenium is a micronutrient – which means it is needed in very tiny amounts. If there is too low or too high levels of selenium in the blood, there will be issues. Ogawa-Wong and colleagues from Hawaii in their 2016 review of scientific literature warn that there may be an adverse impact of selenium supplementation in people who already get enough selenium from food.
  • Side-effects and Precautions: Too much selenium can be harmful. The side-effects can be garlic-breath, nausea, diarrhea, skin rashes, irritability, metallic taste, brittle hair/nails, discolored teeth, problems with nervous system. Extremely high intakes of selenium can lead to severe issues like difficulty in breathing, tremors, kidney failure, heart-attacks and heart failure.
  • Interactions with drugs: Some medications can interact with selenium. Selenium may increase the risk of bleeding when combined with blood thinning medications including aspirin. It may interfere with the cancer fighting ability of chemotherapeutic medicines. It may also reduce the effect of statin-niacin combinations used for lowering blood cholesterol. As with other micronutrients, always talk to your doctor before starting with selenium supplements.
• Zinc: Kazi and colleagues from Pakistan, in their 2008 article, have discussed the importance of zinc and other micronutrients and have found that removal of zinc from the body due to excessive urination in diabetics is linked to lower zinc levels in blood. However, the data has been conflicting and whether diabetes can be reversed or controlled through zing supplementation is still unclear. In 2014 Maruthur and colleagues from USA found that zinc supplementation may be more beneficial to some diabetics than others in prevention and control of diabetes – the reason for this lies in that the small genetic differences play a role in the response to zinc supplementation. Thus, at this point it seems that you will only benefit from taking zinc supplements if you have a certain genetic makeup.
  • Side-effects and precautions: Side-effects of too much zinc intake are nausea, vomiting, loss of appetite, cramps in the stomach, diarrhea and headache. If you take zinc for a very long time, you may have low levels of copper in your body, lower immunity and low levels of HDL(good)-cholesterol. As with any vitamin or mineral in supplement form, you should only take zinc intermittently (Have it for a few days, then stop for another few, then restart). However, listen to what your doctor recommends.
  • Interactions with drugs: Zinc as dietary supplement when taken along with tetracycline antibiotics reduces how much your body can absorb either of these. Zinc can also decrease the absorption of penicillamine (taken for rheumatoid arthritis). The antibiotic and penicillamine should therefore be taken at least 2 hours before taking the zinc supplement. Again, if you are taking any medicines of any kind, talk to your doctor before starting zinc supplements.
• Iron: Although optimum amounts of iron are needed for optimum functioning of our cells and tissues, an increased level of iron is actually harmful. Iron overload for any reason whatsoever can lead to increased incidence of type 2 diabetes although the exact cause for this is unknown. There is also evidence for an increased level of iron being responsible for diabetic complications. Swaminathan and colleagues from USA describe the evidence for these in their 2007 review. Kazi and colleagues from Pakistan found in their study that the levels of iron were high in diabetics as compared to non-diabetics. It is therefore not recommended to take iron supplements if you are a diabetic. If you are anemic, your doctor needs to find out the exact reason for your anemia – if you need to take iron supplements, do this only under your doctor’s supervision.
• Magnesium: You could become magnesium deficient if you have diabetes. Diabetes or insulin resistance causes removal of magnesium along with other minerals from your body due to excess removal of water through urination. Research in the 90s found that there was a link between low magnesium levels in the blood and type 2 diabetes. Research also showed that insulin regulates magnesium metabolism, and that diabetics have lower levels of free magnesium in their cells. Magnesium apparently increases insulin’s ability to activate an enzyme called tyrosine kinase that is used in metabolism of glucose. When there are low levels of magnesium inside the cells it reduces the activity of tyrosine kinase which now cannot utilize the glucose within the cells and this leads to insulin resistance. It was also shown back in 1978 that low magnesium levels can help development of diabetic complications like diabetic retinopathy. A 2013 study on nearly 2000 people by Hata and colleagues from Japan showed that increased magnesium intake significantly protected against development of type 2 diabetes in the Japanese population – especially in those who had insulin resistance, low grade inflammation and a drinking habit. Similar findings were reported by an American study published in 2014 by Hruby and colleagues that was done on over 2500 people and was followed over 7 years. The researchers report that taking magnesium reduces the risk of developing type 2 diabetes – this is especially true for people who are at high risk for developing it due to genetic or physiological reasons. There thus now seems to be sufficient data to recommend magnesium supplementation in diabetics to prevent and control diabetes.
  • Side-effects and precautions: Taking too much magnesium can often result in diarrhea, nausea and abdominal cramps. Excessive magnesium can also cause magnesium toxicity and there are reports of people dying from this. Symptoms of magnesium toxicity include low blood pressure, nausea, vomiting, flushed face, urine retention, and depression. These initial symptoms may progress to muscle weakness, breathing difficulty, extremely low blood pressure, irregular heartbeat and cardiac arrest (heart stops beating). Risk of getting such reactions increases if one has kidney failure or improperly functioning kidneys due to which excess magnesium cannot be removed from the body.
  • Interactions with drugs: Magnesium supplements can reduce absorption of medicines used to treat osteoporosis (bisphosphonates). To avoid this from happening, such medications should be taken at least 2 hours before taking magnesium. Magnesium can also form insoluble complexes with antibiotics like tetracyclines. Again these should be taken minimum 2h before magnesium. Please consult your doctor always before taking magnesium supplements as there may be interactions with other medicines that you may be taking.
  • Dosage: The following table gives you the Recommended Daily Allowance (RDA) for various minerals we have discussed above. The Upper Limit (UL) for each of these is given in red – these are highest intakes not supposed to pose any risk. ND=Not determined. However, please consult your doctor to find out what is the best dosage for you.

	Children 1-8 y	Males 9 to >50y	Females 9 to >50y	Pregnancy 14-50y	Lactation 14-50y
Chromium (mcg/day)	11-15 (ND)	25-35 (ND)	21-25 (ND)	29-30 (ND)	44-45 (ND)
Selenium (mcg/day)	20-30 (90-150)	40-55 (280-400)	40-55 (280-400)	60 (400)	70 (400)
Zinc (mg/day)	3-5 (7-12)	11 (23-40)	8-9 (23-40)	11-12 (34-40)	12-13 (34-40)
Magnesium (mg/day)	80-130 (65-110)	240-420 (350)	240-360 (350)	350-400 (350)	310-360 (350)

Herbs, plants, and spices

• • Cinnamon: Cinnamon is the bark of a particular family of tropical trees. Studies until now have found some blood glucose lowering effect of compounds in cinnamon and cinnamon extract, but the results have been largely inconclusive due to lack of large scale controlled studies on people regarding the efficacy and safety of cinnamon supplementation and whether the effects of cinnamon will last long term. It is thought that the way cinnamon works in reducing blood glucose is by increasing the effect of insulina through different mechanisms like increasing the sensitivity of insulin receptors, activating glucose transport, inhibiting intestinal alpha-glucosidase in a manner similar to the diabetes drug acarbose apart from others.
    • Side-effects and precautions: Side effects of cinnamon are not very well documented in people. Cinnamon in oral form is considered safe for most people in doses up to 6g daily for up to 6 weeks although some people may be allergic to cinnamon or its parts. Cassia type of cinnamon contains large amounts of coumarin which is a blood thinner and could cause liver toxicity (has been only checked in animal studies) when taken in large amounts. It is therefore not advisable to have large amounts of cassia cinnamon.
    • Interactions with drugs: A combination of cinnamon supplement and statins can cause acute inflammation of the liver (acute hepatitis).
  • Seaweed/brown seaweed: Brown sea-weed (wakame) is a rich source of nutrients like eicosapantenoic acid, omega-3-fatty acids, fiber, magnesium and zinc. Most of the studies on it have been done so far only in animals. While studies showing its effect on reducing obesity have been done in the past, it has been found to reduce insulin resistance (but was unable to prevent obesity) and inflammation in one of the more recent (2016) study published by Oh and colleagues from Korea. Insulin resistance and inflammation are hallmark signs of diabetes – and thus wakame seems to have potential in use by the diabetics. One 2011, small, controlled study published by Paradis and colleagues from Canada was done on people. The researchers studied the effect of brown seaweed supplementation on blood glucose and insulin concentrations after meals. They found that there was increase in insulin sensitivity in those who consumed the supplement as compared to those who did not. They also did not find any adverse effects of sea-weed supplementation. While there is some evidence from small studies on humans and on animals, more large scale studies done over a longer term in humans will be needed to be sure of the efficacy and safety of brown seaweed in diabetes.
    • You could take a small amount of this supplement under the care of your doctor.
    • Side-effects and precautions: Some gut discomfort has been reported as a side-effect of eating large amounts of seaweed salad. There is not enough information available on the side-effects and safety of brown seaweed supplements for diabetics. Please remember that seaweed can contain heavy metals. As seaweed is also high in iodine content, excessive intake of dried seaweed can cause thyroid issues as too much iodine is also not good for our bodies. A Japanese study by Michikawa and colleagues found association between seaweed intake and thyroid cancer in post-menopausal women. We therefore recommend caution in taking this supplement and advise you to only take this under consultation with your doctor.
    • Interactions with drugs Brown seaweed also has high vitamin K content and may interfere with blood thinning medications like warfarin (Coumadin). Other interactions are not known as not many studies are carried out. Please talk to your doctor if you are taking any medication before starting this supplement.
    • Dosage: As there are not many clinical studies done on brown seaweed supplementation, the optimum and upper limits of dosage are not known. Please contact your doctor/nutritionist for advice on what dosage will be optimum for you.

Fatty acids and Lipids

• • Alpha lipoic acid (ALA): This is an antioxidant which means that this may protect against cell damage resulting from oxidative stress. A 2012 study by Udupa and colleagues from India compared the effects of three antioxidants – ALA, omega-3- fatty acids, and vitamin E - on insulin sensitivity in type 2 DM. They found that all three showed improvement in insulin sensitivity. There was significant decrease in BMI, waist circumference, HbA1C levels, and total cholesterol in the patients treated with either of these antioxidants as compared to the patients who were given placebo (tablets with no active components). There are several other studies (described in a 2014 review by Gomes and Negrato) that show that ALA may be a useful supplement in reducing diabetic complications. There are also contradicting reports on reduction of blood glucose levels – with some claiming reduction while others finding no reduction in blood glucose levels.
    • Side-effects and precautions: Side-effects are rare but sometimes may lead to insomnia (inability to sleep), fatigue, diarrhea and skin-rash. As it is likely that ALA can reduce blood sugar levels, diabetics should be cautious while taking it. This is also an added risk for diabetics who take medications for diabetes for lowering blood sugar as this could lead to hypoglycemia. Also, from an animal study it is known that ALA can reduce the levels of vitamin B1, so those who already have a vitamin B1 deficiency should not take ALA. Research has also showed that ALA can possibly lower the levels of thyroid hormones, so if you are taking ALA supplements, your doctor needs to closely monitor your thyroid hormone levels to avoid any complications. Safety of ALA has not been tested on pregnant or breastfeeding women, so it should be avoided or taken with caution by such women.
    • Interactions with drugs: ALA can combine with insulin and blood sugar lowering medications leading to hypoglycemia. Closely monitor your blood sugar levels if you take ALA with medications for diabetes. Your diabetes medication may need to be adjusted by your doctor in such a case – so do contact your doctor before taking ALA supplements. ALA can also lower the levels of thyroid hormones – so if you are taking any thyroid regulating medicines, your thyroid function needs to be monitored closely.
  • Omega-3, 6 and 9: Omega 3, 6 and 9 fatty acids are polyunsaturated fatty acids (PUFAs). Omega 3 and 6 are essential fatty acids (EFAs) meaning that although these fatty acids are important for our health, we cannot ourselves make these fatty acids in our body and need an external source. Omega 9 fatty acids are not EFAs as we are able to make this fatty acid ourselves from unsaturated fat.

One study on Eskimos by Ebbesson and colleagues from USA found that diabetes in the Eskimo population was related to fatty acid imbalance with lower concentrations of omega 3 and 6 and higher concentrations of saturated fatty acids and omega 9 fatty acids.

However, none of the clinical trials that have been carried out to date on omega fatty acid supplementation have showed any impact on lowering of blood glucose or HbA1C. On the other hand, there are studies that provide preliminary evidence that these supplements may increase antioxidant capacity in type 2 diabetics, may be helpful against heart disease, high cholesterol, high blood pressure which are complications of diabetes.

• • • Side-effects and precautions: There are usually no negative side-effects of omega 3 fatty acids, but if they occur they include indigestion, belching or diarrhea. You should not take omega 3 if you bruise easily, have a bleeding disorder, or take blood thinners. As a diabetic, or if you have schizophrenia, your body may not be able to use omega 3 fatty acids – so you may be required to increase the intake of Eicosapantenoic acid (EPA) and docodohexanoic acid (DHA) through diet. Type 2 diabetics also may get increased fasting blood sugar levels due to this supplement – you should therefore consult your doctor before taking this. Also if you get omega 3 from fish source, buy it only from a reputable company which tests it for mercury and pesticide residues.

You should not take omega 6 if you suffer from seizures as it can cause seizures. It should not be taken during pregnancy as it can harm the fetus and cause early labor. As omega 6 has inflammatory properties, excess intake of this fatty acid can cause increase in inflammation. There can be gut related side-effects like stomach pain, diarrhea, and nausea. If you are at a risk for prostate cancer, it is recommended that you do not take omega 6 as it may promote the growth of prostate tumors.

Omega 9 generally does not have any side-effects as it is the most common fat in our bodies.

• • • Interactions with drugs: Omega 3, 6, and 9s may increase bleeding time and may therefore increase the risk of much delayed clotting if you are taking blood thinners. Omega 6 may increase the effectiveness of antibiotic ceftazidime, anticancer treatments, and the immunosuppressant cyclosporine. It may also interact with Phenothiazines used for schizophrenia and cause seizures.
    • Dosage: Do not take omega 3 fatty acid supplements in doses above 3g/day. For best dosage suited to you for this and the other omega fatty acids, please talk to your doctor.
• Conjugated Linoleic Acid (CLA): CLAs are a group of at least 56 isomers (molecules with same formula but with different chemical structures) of naturally occurring PUFAs called octadecadienoic acids. Commercial supplements are usually a 50:50 mix of two of the isomers. Dramatic effects of CLA on reduction in obesity were observed in mice, but after many clinical studies on people, which are reviewed in details in the 2015 article by Benjamin and colleagues from India, USA and Austria, it is still not possible to make a definitive statement about benefits of CLA on body composition. This is because the studies contradict each other and also there are very few long-term studies. Benjamin and colleagues have also reviewed current research on CLA and its effect on diabetes. While there is some evidence from animal studies that CLA supplementation can increase insulin sensitivity, very few studies are done in humans. Those done in humans show very little effect of CLA on insulin sensitivity and some studies even show a negative effect the isomers (9- and 10-CLA) which were found to increase insulin resistance. All in all, the data on CLA is inconclusive with some positive results and some adverse effects on diabetes. Considering the negative effects, it is not advisable for diabetics to use CLA supplements.
  • Side-effects and precautions: As mentioned above, the worrying side-effect of CLA supplementation for diabetics can be an increase in insulin resistance and oxidative stress making this supplement harmful to diabetics to some extent. CLA can also cause irritation of the gut and associated gut-symptoms like indigestion, diarrhea, nausea, and bloating. However, these effects can be temporary. If you are pregnant or nursing, you must be extra cautious while taking this supplement as it is known to reduce the fat content in milk. As milk is the only source of fat for the infant, low fat milk can lead to growth and metabolic issues in the infant.
  • Interactions with drugs: Not many studies have been done and not much is known about interaction of CLA with different medications. If you are taking any medications when your doctor recommends you to take CLA, please discuss with your doctor any possible interactions.
  • Dosage: Based on the evidence we cannot recommend the use of CLA by diabetics. If your doctor would like you to take this supplement, he/she will recommend the best dose for you, your body weight and your metabolism.

Protein/amino acid

• Protein powder: Protein powder supplements are usually whey supplements. Whey is one component of milk protein and comprises about 20% of milk protein. It is a good source of amino acids and the peptides produced its digestion have bioactive properties. Diets with low glycemic index are thought to be protective against type 2 diabetes – adding protein in the diet reduces the glycemic index and is thus useful. There is a 2010 study by Pal and Ellis from Australia which shows that whey protein meal produces a higher insulin response and reduced appetite compared to casein, egg, tuna or turkey proteins. A 2009 study by Petersen and colleagues from USA found that whey protein supplement reduces after-meal rise in blood sugar. There is suggestion of long-term improvement of insulin sensitivity when whey protein is taken for 12 weeks. Frid and colleagues from Sweden had already found in 2005 that such an effect is also seen in diabetics – adding whey to a meal high in easily digesting carbohydrates helped stimulate insulin in blood and reduced after-meal high blood glucose. Apart from insulin, whey proteins also seem to increase the incretin hormone release in the gut as was showed in a clinical trial by Jakubowicz and colleagues from Israel in 2014. On the other hand, Smith and colleagues from USA found in 2015 that whey protein induced insulin resistance by impairing glucose disposal. In 2016, Allerton and colleagues from UK found no impact of taking whey protein with a carbohydrate rich breakfast on blood sugar levels in healthy men although there was an increase in insulin post-breakfast with whey protein. In the light of slightly conflicting data on the use of whey protein in regulation of insulin and blood glucose, more studies are needed to make any claim.
  • Side-effects and precautions: People allergic to milk or milk products should not take whey or casein supplements. Allergic reactions to whey have been reported. There may be some risk of developing insulin resistance – but the evidence for this is too thin so far.
  • Interactions with drugs: Diabetics should be careful taking whey supplements as this may reduce blood sugar and when taken in combination with sugar lowering drugs it could cause hypoglycemia (low-blood sugar).
  • Dosage: According to Mayo Clinic, this supplement is likely safe to take as a single dose of up to 50g or when 30g is taken orally for 6 months. However, please contact your doctor for the best dosage for you.
• Glutamine: L-glutamine, when given with a meal, has been found to increase the GLP-1 and insulin secretions and to decrease the after-meal high blood sugar in type 2 diabetics. This effect was described in a 2009 study by Greenfield and colleagues from the UK which was done on patients with well-controlled diabetes. In 2011, Samocha-Bonet and colleagues from Australia showed in a clinical trial that glutamine could be a novel agent, with or without sitagliptin (a diabetes medication), to stimulate GLP-1 concentration and to reduce high blood sugar after meals. The same research group did another clinical trial (published in 2014) to study the effect of glutamine on blood sugar with or without sitagliptin and also studied the safety of its supplementation in type 2 diabetics. They found that daily intake of glutamine for 4 weeks, with or without sitagliptin, reduced HbA1c in well controlled type 2 diabetics on metformin. They also found that such supplementation caused modest decrease in the concentration of circulating blood cells and total protein and albumin. They therefore suggest that more studies need to be done on this side-effect over a longer term. Glutamine therefore may be recommended to diabetics under the care of their doctors. However, please note that there are no studies on people with uncontrolled diabetes – so if you have uncontrolled diabetes, please make sure that you talk to your doctor before you take this supplement.
  • Side-effects and precautions: Do not add glutamine to hot beverages as it destroys glutamine. It should not be taken by people with kidney or liver disease or Reye syndrome. Those with psychiatric disorders or history or seizures should use glutamine with caution as it may worsen their condition. Check out if there are other components added to the product and ascertain that these will not cause you any harmful side-effects.
  • Interactions with drugs: Glutamine may increase effectiveness of colon cancer treatment with doxorubicin, methotrexate and 5-fluorouracil. There is some evidence that it may decrease the nerve damage caused by paclitaxel used to treat breast cancer and other cancers. Some studies show that it may promote tumor growth. It is uncertain if it is safe to use glutamine by cancer patients.
  • Dosage: Talk to your doctor regarding the dosage suited to you.
• Pre-workout supplement: Pre-workout supplements claim to improve energy, alertness, strength, power, and body composition. These supplements often are a blend of undeclared components like caffeine, creatine, guarana along with a single declared main component. The hidden ingredients are stimulants and work to increase your blood flow, focus, heart-rate and give you a slight high of feeling well. According to the International Society of Sports Nutrition position stand, diabetics and those with heart, metabolic, kidney or neurological disease should avoid the use of stimulants unless approved by their doctors. Although coffee consumption is linked with lowered risk of developing diabetes as was shown by an analysis of scientific works by Huxley and colleagues in 2009, people who already have diabetes may suffer from negative effects of caffeine as was shown by another analysis of controlled trials in diabetics by Whitehead and White in 2013. Moreover, pre-workout supplements may contain excessive doses of some compounds. Apart from this, they may contain dangerous components (for anyone). As a diabetic therefore you should avoid using pre-workout supplements as the hidden components may be especially harmful for you.

Hormones and neurotransmitters

• Melatonin: Melatonin is a hormone that regulates and controls other hormones and our body clock. We naturally make this hormone in our pineal gland, the secretion of which into the bloodstream peaks in the night. To get good sleep in night, it is important that the melatonin is secreted a lot in the night and the least during the day. When this balance is disturbed, our sleep is disturbed. McMullan and colleagues from USA showed in 2013 that women who secreted lower melatonin were at higher risk for developing type 2 diabetes. Another study by Matthews and colleagues also from USA found in 2012 that teens that did not get enough sleep were at higher risk of developing type 2 diabetes. A study by Greico and colleagues in 2013 on diabetics who were given melatonin supplementation showed that melatonin supplementation may reduce oxidative stress and improve blood-sugar control. Another random-controlled study by Rezvanfar and colleagues from Iran showed that bed-time supplementation with melatonin improved the control of diabetes.
  • Side-effects and precautions: Vivid dreams or nightmares, stomach cramps, dizziness, headache, irritability, decreased libido, enlargement of breasts in men, reduced sperm count can be some of the side effects according to University of Maryland Medical Center. Pregnant or nursing women should not take melatonin as this can interfere with pregnancy and fertility. There can be disruption of body clock if you take too much melatonin. People with depression should take melatonin only under supervision as it can increase depression.
  • Interaction with drugs: Some of the medications that melatonin can interfere with are anti-depressants (may reduce their effect), steroids and immune-suppressants (may make these ineffective) blood pressure medications (may reduce their effect), antipsychotic medications (may reduce certain side-effects of the drug), Birth control pill (as these increase your melatonin, taking supplements may give you more than healthy levels of it), blood thinners (may increase the risk of bleeding).
  • Dosage: It is best to start with a low dose (near what our body produces which is less than 0.3mg/day) and increase it gradually. Your doctor will help you decide the most appropriate dose for you
• GABA: Gamma amino butyric acid (GABA) is a neurotransmitter that reduces nerve excitation and regulates the muscle tone – in simple words, it is a calming neurotransmitter. We normally produce it in our brains and certain microbes in our gut also produce it. GABA response can be reduced due to genetic reasons, inadequate diet, and long-term stress. Its deficiency is connected with anxiety disorders, seizure disorders and other neruo-psychological conditions. While there is some evidence from animal studies that GABA may be useful in type 1 diabetics by protecting and regenerating islet beta cells that make insulin, there is not much known in relation to type 2 diabetes. Even if GABA is used for anxiety disorders and other neurological disorders, it is not known how GABA can exert its effect in the supplement form – this is because GABA is not very well known to enter the brain from the bloodstream (it generally cannot cross the blood brain barrier). Boonstra and colleagues from Netherlands and Germany have looked at the evidence for the use of oral GABA supplements for anxiety and other neurological issues and have suggested that GABA may act via the Gut Nerve System but more research will be needed to prove or disprove this. The researchers say that it is too early to be able to say that GABA can reach the brain in sufficient amounts to have a biologically relevant effect. Thus, so far there is no evidence that supports the use of GABA supplements in type 2 diabetes or prediabetes.

Enzymes/probiotics/prebiotics

• Enzymes: There is evidence that type 2 diabetics who have the condition for a long time can also have a condition called Exocrine Pancreatic Insufficiency (EPI) – EPI is a deficiency of pancreatic enzymes like amylase, protease and lipase which help in digestion of food. At least 30% of diabetics suffer from mild to moderate EPI and 19% have severe EPI according to a 2003 study by Hardt and colleagues from Germany. As the food does not get digested properly, it leads to gut symptoms like pain in the stomach, bloating, and fatty and loose stools that are foul smelling. It is still unsure whether diabetes causes EPI or EPI can also cause diabetes. Thus, management of EPI may be important not only for management of gut symptoms in diabetes, we can speculate that it may be important in reducing the risk of getting diabetes and could therefore be an important thing for prediabetics. Supplementation with digestive enzymes could be a useful management strategy as well. These supplements are mixtures of enzymes that help digest starch (amylase), protein (protease) and fats (lipase). Such a therapy is called PERT (Pancreatic Enzyme Replacement Therapy). Using replacement digestive enzymes in consultation with your doctor/dietician in prescribed doses along with a well-balanced diet can be helpful.
  • Side-effects and precautions: While we suggest using digestive enzyme supplements, you should be aware that using such enzymes long-term may shut-down your own enzyme production completely leading to a complete dependence on these enzymes. It is therefore suggested that in consultation with your doctor, you should pursue alternate methods like yoga to stimulate your pancreas to function properly and improve your digestion. You can find the side-effects of these enzymes on the leaflet that comes along with the enzymes, which may include nausea, stomach pain, diarrhea and constipation.
  • Dosage: You should normally take these supplements with a meal or snack. You should consult your dietician for a dose appropriate to suit your level of EPI and your food intake.
• Prebiotics and Probiotics: Research has found some evidence that apart from genetics and other external factors like western diet and vitamin D deficiency, gut microbes may play an important role in diabetes by contributing to low-grade inflammation which in turn changes normal glucose tolerance to prediabetes and diabetes. This data was reviewed in an article by Barengolts from USA in 2013. They found that type 2 diabetics have decreased diversity in their gut microbes – so instead of the large variety of bacteria that they should normally have in their gut, they have increased population of a certain type of bacteria called bacteroides. Prebiotics are food for good and beneficial gut bacteria – typically these are fibers (please refer to the “fiber” section of this article to know more about fiber supplementation and diabetes). Barengolts concluded from the available evidence that prebiotics apart from vitamin D supplementation may be useful in managing prediabetes and type 2 diabetes. If your gut flora has changed in the favor of the bad bacteria like bacteroides, it may be important for you to take probiotics and have enough prebiotics to support their growth.
  • Side-effects and precautions: It is important to make sure that you are buying your probiotics from a reliable source. You should check the expiry date and not use these past the expiry date. This is because probiotics are live bacteria and past the expiry date, there may not be enough living bacteria to give you any positive effect. Probiotics are generally safe to use and should not cause any side-effects. However, some temporary side-effects would include bloating and gas. Rarely, probiotics with S. boulardii can cause increased thirst and constipation. In extreme rare cases, systemic infection with probiotics may occur in people who have suppressed immunity, have had surgery, or have other serious underlying conditions. Prebiotics on the other hand can cause gas and bloating. With large doses, there can be stomach pain and diarrhea and sometimes also gastroesophageal reflux (stomach contents go back into the esophagus). It is better to get prebiotics from natural sources as these are less processed – so including fiber in the form of vegetables in your diet is better.
  • Dosage: You need to talk to your doctor about which probiotic may be useful for you and at what dosage – this will depend on your overall condition and sensitivity.

Other

• Creatine: Creatine is a natural amine in the body. It is made partly by our kidneys, liver and pancreas and is also taken from food. It is then mainly transported to the skeletal muscles, brain and testes. While it is mostly used as an athletic performance supplement, there are studies that have found its use in different health conditions including diabetes. A study by Gualano and colleagues from Brazil published their 12 week study on 25 type 2 diabetics where they reported that supplementation with creatine combined with exercise routine improved blood sugar control. However, there are not many long-term, studies on a large number of people for the effect of creatine on diabetics. The side-effects of creatine on diabetics are also not well studied. It is therefore not advisable that you take creatine unless and until your doctor recommends you to. There are no recommendations for creatine by the Office of Dietary Supplements (ODS).
  • Side-effects and precautions: Creatine puts stress on your kidneys to remove excess of it and could lead to kidney damage. If you are a diabetic, it is likely that your kidneys are over-functioning (earlier stages) or under-functioning (later stages) and creatine would put extra stress on them. That creatine should not be taken by people with kidney issues is already known. It could therefore potentially be dangerous for diabetics to take creatine. Creatine also causes an increase in blood pressure and is again therefore not recommended for diabetics. Additionally, it has a potential to reduce blood-sugar and therefore may cause hypoglycemia in diabetics if taken without monitoring and with other drugs. Other side-effects of creatine include abnormal heart rate, aggression, lack of appetite, anxiety and depression, asthmatic symptoms, confusion, constipation, dehydration, diarrhea, fainting, fever, headaches, and many others which can be found on the website of Mayo Clinic.
  • Interactions with drugs: Creatine should be used with extreme caution in people taking any drugs that are cleared through kidneys or that are toxic to the kidneys and liver, caffeine and caffeine containing medicines, mood-controlling drugs, chemotherapy, cholesterol lowering agents, and non-steroidal anti-inflammatory drugs (NSAIDs) as there may be adverse interactions with these drugs. Creatine could interact with many other drugs as well, so please consult your doctor before you start creatine.
  • Dosage: As we do not recommend the use of Creatine by diabetics, we are not including this information here. In a special case that your doctor/nutritionist would like you to use this, they will be able to recommend the best dosage for you.
• Methylsulfonylmethane (MSM): This is an organic sulfur compound and is known for its benefits on joint health. MSM is supposed to have antioxidant and anti-inflammatory effects. There are no studies on the effectiveness/adverse effects on diabetics. Although it is mentioned that there are no side-effects apart from gastrointestinal discomfort in those suffering from osteoarthritis, it is difficult to know what impact this could have on a diabetic because when a person has type 2 diabetes there is issues on many levels of body function. In absence of any studies on diabetics, we do not recommend you to take MSM.
• Nitric oxide (NO): NO is an important molecule that has extensive role in metabolic functions, health of blood vessels, and cell functions. Regulation of its metabolism is very important especially in type 2 diabetes as the enzyme that makes this molecule is under the control of insulin. This means that if there is insulin resistance, NO generation will be disturbed. There is research that shows that there is impaired NO metabolism in type 2 diabetes especially when there are kidney disorders involved. A 2015 research by Adela and colleagues from India have showed that there actually may be an increase in NO levels in diabetics due to high blood glucose levels. There are no controlled human studies on the relation between NO and diabetes (obviously, as it seems like taking NO supplements will be more harmful to diabetics than useful). We therefore do not recommend you to take NO supplements.
• Fiber: Fiber is present in all plant based food as a mix of soluble and insoluble forms. Both of these are important for the health of the gut and for proper bowel movements. Fiber is also food for beneficial gut bacteria. A typical US diet is considerably low in fiber. Research has showed that dietary fiber reduces the risk of type 2 diabetes. In 2012, Post and colleagues from USA analysed 15 controlled studies done on people and found that there was sufficient evidence for fiber supplementation for type 2 diabetes and that this can decrease fasting blood glucose and HbA1c.
  • Side-effects and precautions: Always drink a glass of water with fiber supplements and 6-8 glasses of water throughout the day. Not doing this puts you at a risk from choking due to swelling of these supplements. NEVER take this supplement if you have difficulty swallowing or have impacted stool (a constipation complication). Side-effects may include chest pain, vomiting, difficulty breathing or swallowing – in such cases seek immediate medical attention. It can cause gas and bloating. In rare cases, long time use of fiber supplements can cause allergic reactions.
  • Interactions with drugs: Please contact your doctor before starting fiber supplements if you are taking any of the following medications: Antidepressants – as fiber may lower the levels and effectiveness of the antidepressant, diabetes medications – as fiber regulates blood sugar and may also reduce the absorption of some of these medicines, medicines to control seizures – as fiber may reduce absorption and effectiveness of the medication, cholesterol lowering medicines – as fibers may further lower your cholesterol to a dangerous level. As this is not an exhaustive list, as usual always contact your doctor before starting fiber supplements especially if you are taking any other medications.
  • Dosage: While the recommended dose of fiber is 25-30g of fiber a day, you need to talk to your doctor regarding the right form and dosage of fiber for you.

Selection of supplements: Is there a reason why you should be choosy about your supplements? Yes, there are not one but a few reasons why you should select your supplements with care:

1. 1. You are a diabetic: Being a diabetic your body is not functioning at its optimum. This puts you at risk for many more side-effects as compared to a person who does not have diabetes. Also, the fact that you most likely would be taking some medication for your diabetes or its complications, you need to be wary of the interactions that the supplements may have with your medications.

What you can do: Read the labels carefully. Find out the composition of different supplements and check whether you could have potential side-effects or drug interactions. Check the dosage – it should be optimum for you. If you are uncertain, always contact your doctor or pharmacist.

1. 1. You want to get quality products: The FDA (food and Drug Administration) has established good manufacturing practices (GMPs) so that their identity, purity, strength and composition are ensured. These guidelines also prevent inclusion of wrong ingredients and contamination. They also ensure that the supplement is labeled properly. FDA also periodically inspects the manufacturing facilities. Apart from FDA, agencies and organizations like the US Parmacopeia, ConsumerLab.com and NSF international offer quality testing and provide their seals of approval. Please note: even if a product has these seals, it does not guarantee the safety and efficacy of the product.

What you can do: Buy supplements from companies that ensure that their products are tested by a third party organization like those mentioned above.

1. 1. You want to avoid scams: As the incidence of diabetes increases around the globe, frauds and scammers abound the field to make a quick buck from gullible people who are fed up with their condition and especially those who would like a quick-fix. Market (especially the online market) is filled with dubious products with tall claims.

What you can do: According to FDA, you will know whether the product is a scam by keeping an eye out for the following in combination–

1. 1. The supplement claims to be effective in a wide range of diseases.
   2. Testimonials from people claiming that their issues vanished by taking that supplement. Remember, testimonials can be faked. Make sure that the company presents you with the right scientific evidence.
   3. The product claims to fix your woes quickly – within few hours, days or weeks.
   4. Product claims to be “all natural” but does not present you with the dangers of some of the ingredients that despite being natural can be very dangerous.
   5. Product claims to be “miracle cure”.
   6. Claims to be FDA approved. Yes, this is correct! Dietary supplements are not required to be FDA approved – so FDA actually does not give approvals for dietary supplements.

If you are unsure, talk to your doctor about the product you are interested in trying.

If I am diabetic can I take testosterone supplement?

Studies like the one by Dandona and colleagues from USA (2010) have found that there may be a correlation between low testosterone levels in men and type 2 diabetes. Other studies like the one by Boyanov and colleagues from Bulgaria (2003) and by Lee and colleagues from China (2005) have found that testosterone supplementation may improve insulin sensitivity and blood sugar control if the diabetics have low testosterone levels. An analysis by Ginsburg and colleagues from USA found low incidence (1.3%) of adverse effects of testosterone supplementation over long term. So it may be useful for you as a diabetic to take testosterone supplements if you know that you have low testosterone levels. However, testosterone is a hormone and should be taken carefully after consultation with your doctor.

Are there any prevention type supplements for prediabetics?

Magnesium, vitamin K, and to some extent zinc may have preventive role against diabetes.

I am type 2 diabetic but I work-out. Is it okay to take pre-workout supplements?

No, it may not be good for you to take pre-workout supplements. Please check out the details in this article.

What do you think about selenium for prediabetics?

Selenium can be used by prediabetics if they are certain that they have very low selenium levels. In case they do have low selenium levels, it may be beneficial taking selenium supplement as selenium behaves like insulin.

I have heard from friends that sweaweed/brown seaweed supplement can help is that true?

Taking seaweed/brown seaweed could be beneficial for diabetics when taken in small doses over short term. Adverse effects of taking this supplement for a long term are not known.

Can glutamine help prediabetics?

GLP-1 response to glucose is reduced in prediabetes. Glutamine increases the GLP-1 response and insulin secretion. So it may be useful in prediabetes.

What do you think about cla supplement for prediabetics?

CLA supplements are not advisable for diabetics or for prediabetics as there is a risk that these may increase your insulin resistance.

TheDiabetesCouncil Article | Reviewed by Dr. Sergii Vasyliuk MD on June 02, 2020