Diabetes Supplements Research: What Studies Say About Benefits and Risks

Many people with diabetes will try vitamin, mineral and herbal supplements in an attempt to manage their blood glucose levels.

Many of these supplements have been studied in scientific research including berberine, magnesium, cinnamon, vitamin D, chromium and omega-3 fatty acids.

While some studies have shown promising results, these findings do not mean that they are safe, effective or suitable for everyone.

There can be variation in the quality of research, who is involved in the research, type of supplement and length of the study.

Overall, evidence supporting the use of most supplements to improve diabetes control remains limited.

The American Diabetes Association’s 2026 Standards of Care do not recommend routine supplementation with micronutrients, such as magnesium or chromium, or herbs and spices, such as cinnamon and aloe vera, for improving blood glucose levels.

This guide will look at the evidence from clinical research, areas where there are still uncertainties and how someone with diabetes should think about using a supplement. We’ll also explain why addressing a known deficiency is different to taking a supplement in the hope that it will help treat diabetes.

Medical Note: This information has been provided as a general educational service only and should not be used to replace personal advice from a qualified health professional. Please do not stop, start or alter diabetes medication or supplementation without first discussing it with your qualified healthcare professional.

Article Index

What Does Diabetes Supplements Research Show?
What Can Supplements Actually Do?
How to Evaluate Research on Diabetes Supplements
Vitamin D and Diabetes Research
Magnesium Supplements and Blood Glucose
Chromium and Diabetes Research
Cinnamon and Other Herbal Supplements
Berberine for Type 2 Diabetes: Research and Safety
Psyllium and Soluble Fiber
Alpha-Lipoic Acid and Diabetic Neuropathy
Omega-3 Fatty Acids and Diabetes
B Vitamins, Zinc, Selenium and Antioxidants
Supplement Safety, Interactions and Regulation
What Do Current Diabetes Guidelines Recommend?
Frequently Asked Questions
Key Takeaways
References

What Does Diabetes Supplements Research Show?

Research into diabetes supplements has increased, with scientists investigating which nutrients and plant compounds may assist with insulin sensitivity, glucose uptake, inflammation, lipid levels or other metabolic factors.

The significance of a finding depends on the outcome measured. A supplement may alter a lab result but may not help with managing diabetes in the long term and preventing complications.

The National Center for Complementary and Integrative Health (NCCIH), part of the US National Institutes of Health, reports that some studies have suggested possible benefits from compounds such as berberine, cinnamon and chromium. However, many studies have been small or have differed in their participants, formulations, amounts and treatment periods. The available evidence is not sufficient to establish most supplements as effective treatments for diabetes or its complications.

The ADA’s 2026 Standards of Care recommend that healthcare professionals assess whether patients are using supplements. Routine supplementation with micronutrients or herbal products is not recommended for improving glycemic control.

It doesn’t mean that nutritional deficiencies shouldn’t be considered. If an individual is known to have a deficiency they may require treatment. However, this is different from using supplements to treat diabetes.

For a broader overview of products discussed in this area, see our guide to best diabetic supplements. This research article has a different purpose: it examines the evidence and its limitations rather than ranking products.

What Can Supplements Actually Do?

A healthcare professional may recommend vitamin B12 supplementation for someone with a confirmed deficiency or magnesium supplementation when low magnesium levels need to be corrected.

Taking additional nutrients is not automatically beneficial for someone who already has adequate nutritional levels, and it should not be assumed to improve blood glucose control.

Research on diabetes supplements generally examines several types of outcomes:

Fasting blood glucose: The amount of glucose in the blood after a period without food.
Post-meal blood glucose: The rise in glucose after eating.
HbA1c: A measure that reflects average blood glucose over approximately two to three months.
Insulin sensitivity: How effectively the body’s cells respond to insulin.
Blood lipids: Measures such as triglycerides and cholesterol, which are relevant to cardiovascular health.
Complication-related outcomes: For example, symptoms associated with diabetic neuropathy.

A trial may show improvements in only one of these measures. This means it is important to look at what was measured.

Supplements should not be considered as an alternative to taking prescribed drugs for diabetes, providing individualized nutrition, exercise, blood sugar monitoring and routine medical care.

For more background, read our guide to understanding the impact of dietary supplements on blood sugar levels.

How to Evaluate Research on Diabetes

Supplements

Not all scientific studies provide the same level of evidence. Understanding the type of research can help readers avoid interpreting early findings as established treatment benefits.

Randomized Controlled Trials

A randomized controlled trial (RCT) assigns participants to different groups, often comparing a supplement with a placebo or another intervention.

Randomization can reduce differences between groups and improve the reliability of the comparison. However, a small or short trial may be unable to establish lasting benefits or detect uncommon adverse events.

Researchers should also report whether participants were taking diabetes medication, whether their nutritional status was assessed and whether the supplement formulation was clearly described.

Systematic Reviews and Meta-Analyses

A systematic review uses a predefined method to identify, assess and summarize relevant studies. A meta-analysis may then statistically combine results from several studies when it is appropriate to do so.

These methods can provide a broader understanding of the available evidence. However, combining studies does not automatically correct weaknesses in the original research.

A systematic review may combine trials that differ in supplement formulations, doses, treatment duration and participant characteristics. These differences can make the overall findings more difficult to apply to individual patients.

Why Study Quality Matters

When evaluating research on diabetes supplements, consider the following questions:

– Did participants have type 1 diabetes, type 2 diabetes, prediabetes or another condition?

– How many participants completed the study?

– Was the supplement compared with a placebo?

– How long did the study last?

– Were the findings clinically meaningful or limited to short-term laboratory changes?

– Were side effects and medication interactions reported?

– Were the findings consistent across studies?

– Was the research independently funded?

– Were any conflicts of interest disclosed?

Statistical significance does not necessarily mean that an improvement is large enough to make a meaningful difference to health.

Vitamin D and Diabetes Research

Vitamin D plays a role in bone health, as well as many other bodily functions. It has been studied by researchers to see if it affects insulin secretion, insulin sensitivity and type 2 diabetes risk.

Observational studies have shown associations between low vitamin D and increased risk of type 2 diabetes. Association does not mean causation, so other factors such as weight, physical activity levels and overall health may affect vitamin D levels and diabetes risk.

Clinical trials have shown mixed results.

Supplementing vitamin D has not consistently shown improvements in glucose regulation or preventing progression from pre-diabetes to type 2 diabetes in those with adequate vitamin D levels (NIH Office of Dietary Supplements).

While some analysis has indicated potential benefits in specific populations, especially those with low baseline vitamin D, the ADA do not recommend supplementing vitamin D in those with type 1 or type 2 diabetes who are not vitamin D deficient.

In practice, vitamin D deficiencies should be considered and treated if appropriate. Supplementing vitamin D should not be used to reduce blood glucose.

Too much vitamin D can cause issues. Very high intakes can cause increased blood calcium levels, kidney problems and other complications.

Source: NIH Office of Dietary Supplements — Vitamin D.

Magnesium Supplements and Blood Glucose

Magnesium is an essential mineral, which plays a role in muscle and nerve function, energy production and glucose metabolism.

Some research has studied if magnesium supplements can improve insulin sensitivity and blood glucose levels in people with type 2 diabetes.

A 2022 systematic review and meta-analysis included 18 randomized trials involving 1,097 people with type 2 diabetes. The findings suggested that oral magnesium supplementation might improve some measures of glycemic control, particularly HbA1c at certain amounts and treatment periods.

However, the evidence for fasting blood glucose was less certain, and the authors concluded that the available clinical trials were not sufficient to establish treatment guidelines.

Some people with type 2 diabetes may have low magnesium levels. Increased urinary magnesium losses can contribute to this in certain individuals. However, this does not mean that everyone with diabetes needs magnesium supplementation.

A confirmed magnesium deficiency should be assessed and managed appropriately. This is different from recommending magnesium supplements to everyone with diabetes for the purpose of lowering blood glucose.

Taking high doses of magnesium can cause diarrhea, nausea and cramps. Those with impaired kidney function may be particularly concerned about taking too much magnesium as the kidneys are an important organ in removing excess magnesium.

Those with kidney disease, or those taking medication that can affect magnesium levels should talk to their healthcare professional.

Source: NIH Office of Dietary Supplements — Magnesium.

Chromium and Diabetes Research

Chromium is a trace element found in wholegrain foods, meat, vegetables and some fruits. It has attracted attention due to its potential role in insulin function and glucose metabolism.

Some studies and reviews have found benefits on fasting blood glucose or HbA1c values in those with type 2 diabetes who have received chromium supplements. However other studies have found little or no meaningful benefit.

Due to variations in the type of chromium supplement used, study design, population studied and length of treatment it is difficult to come to any firm conclusions.

The ADA’s 2026 Standards of Care do not recommend chromium supplementation for glycemic benefits.

Also high supplementation doses have been linked to reports of kidney and liver issues. Risk will vary depending on the product.

Current evidence does not establish chromium supplementation as a treatment for insulin resistance or diabetes. A healthcare professional can assess whether there is a specific reason to investigate or correct a nutritional deficiency.

Source: NCCIH — Diabetes and Dietary Supplements.

Cinnamon and Other Herbal Supplements

Cinnamon is commonly found in food products and has been looked at as a supplement to help regulate blood glucose levels.

Some reviews have shown that cinnamon can lower fasting blood glucose levels or improve insulin resistance in people with prediabetes or type 2 diabetes. However there are several variations in the studies including species of cinnamon used, cinnamon formulation, dose and length of treatment so results were inconsistent and cinnamon cannot be recommended as a treatment for diabetes.

The ADA does not recommend routine cinnamon supplementation for glycemic benefits.

There are also differences to consider when taking cinnamon in normal food quantities compared to concentrated extracts or large doses.

Cassia cinnamon, a commonly used variety, varies in its coumarin content. Large or prolonged intakes may be a concern for some people, particularly those with liver disease.

What About Fenugreek, Bitter Melon and Gymnema?

Fenugreek, bitter melon, gymnema, ginseng and aloe vera have also been studied.

Research into this area is generally small scale, often with varied formulations and inconsistent methodology. Some small studies show potential effects on glucose related measures.

According to NCCIH, available research has not established that herbal supplements are effective for preventing or treating diabetes or its complications.

It is also important to note that herbal remedies are not always safe. There can be side effects from herbal ingredients, they can vary in strength and may interact with prescribed medication.

Berberine for Type 2 Diabetes: Research and Safety

Berberine is a compound derived from plants such as barberry and goldenseal which has been the subject of research due to its potential effects on glucose and other metabolic factors.

A systematic review and meta-analysis looking at 50 randomized controlled trials and 4150 individuals was carried out in 2024. They found that taking berberine alone or in combination with glucose-lowering drugs can lead to improvement in several factors including fasting and postprandial glucose levels. In some analysis looking at combination treatments there was also a reduction in HbA1c.

There are interesting findings here but we cannot conclude that it is an established treatment.

These findings need to be interpreted cautiously because the trials differed in their methods, participants and berberine preparations. Most of the included studies were conducted in China, so the findings may not apply equally to every population. More well-designed research is needed to establish long-term effectiveness and safety.

Berberine Safety Considerations

Berberine can cause gastrointestinal problems including nausea, diarrhea, bloating and constipation, and may interact with certain medications. If you’re currently on any prescription medications then speak to your doctor or pharmacist first.

It shouldn’t be used while pregnant, breastfeeding or given to infants. The NCCIH notes that it can result in harmful build-up of bilirubin in infants.

There is no established evidence-based basis for using berberine instead of prescribed diabetes medication or for selecting a self-treatment dose based on these research findings.

These results warrant further investigation, but they should not be interpreted as a reason to self-treat diabetes with berberine.

Research source: 2024 Systematic Review and Meta-Analysis of Berberine in Type 2 Diabetes.

Psyllium and Soluble Fiber

Psyllium is a soluble fiber which is extracted from the husks of Plantago ovata seeds. It can create a gel-like product when mixed with liquid.

Research has been conducted into whether Psyllium affects glucose levels after meals, fasting glucose levels, HbA1c levels and insulin resistance.

A systematic review and meta-analysis was conducted in 2024 looking at 19 randomized controlled trial consisting of 962 participants. It was found that Psyllium reduced fasting glucose levels, HbA1c levels and insulin resistance compared to placebo.

However there was heterogeneity between the studies. Some results were variable depending on how much Psyllium was taken and for how long.

However, the studies differed considerably in their results, with substantial heterogeneity across the glucose-related outcomes. The findings should therefore be interpreted cautiously rather than treated as definitive evidence of a consistent benefit for everyone with diabetes.

This gives a reason to look into soluble fiber further but does not support using Psyllium supplements as an alternative to diabetes medications.

It is important to consider that fiber supplements are different to having a high fiber diet. Fiber can be found in many foods such as beans, lentils, vegetables, whole fruits and whole grains along with other nutrients.

Psyllium can give bloating and digestive issues. It must be taken with enough water. As some fiber products can affect the absorption of some oral medications, if you are on regular medication it is advised to speak to your pharmacist to find out the correct time to take it.

Research source: 2024 Systematic Review of Psyllium, Fasting Blood Glucose and HbA1c.

Alpha-Lipoic Acid and Diabetic Neuropathy

Alpha-lipoic acid is a compound involved in energy metabolism. It has antioxidant properties and has been investigated for its potential effect on blood glucose, lipids and complications of diabetes.

There are varying results.

A 2019 systematic review and meta-analysis of 10 studies involving 553 people found no statistically significant advantage of alpha-lipoic acid over placebo for HbA1c, fasting blood glucose, post-meal glucose or lipid outcomes in people with uncomplicated type 2 diabetes. The review did report an improvement in glutathione peroxidase, a marker of antioxidant activity, but this does not establish a meaningful clinical benefit.

Research looking at neuropathy in diabetics has shown mixed results with some reviews showing possible benefits with nerve pain and others showing no clear benefit.

Evidence relating to neuropathy symptoms should not be interpreted as proof that alpha-lipoic acid improves blood glucose control or prevents nerve damage.

Common side effects include headaches, indigestion, nausea and vomiting. If you have diabetes, speak with your healthcare professional before using this supplement, particularly if you take medications or other supplements that affect blood glucose levels.

Source: NCCIH — Diabetes and Dietary Supplements.

Omega-3 Fatty Acids and Diabetes

Omega-3 fatty acids (particularly EPA and DHA) can be found in oily fish and some dietary supplements.

Omega-3 has been widely researched for its effect on triglycerides, heart health and metabolic markers in those with and without diabetes.

Studies looking at the effects of omega-3 supplementation on blood glucose levels have shown mixed results.

Some reviews have reported changes in fasting blood glucose or insulin resistance, while others have found no significant effect on HbA1c or fasting blood glucose. The studies used different omega-3 formulations, participant populations, doses and treatment periods, making their findings difficult to compare.

The NIH notes that omega-3 fatty acids can reduce triglyceride levels. However this does not mean they improve diabetes control.

Eating fish as part of a healthy, balanced diet is different to taking concentrated fish oil supplements. Not all supplement products will provide the same benefits.

Omega-3 can cause gastrointestinal side effects and can interact with drugs which affect blood clotting. If you are currently taking anticoagulants or any other relevant medication speak to your healthcare professional.

Sources: NIH Office of Dietary Supplements — Omega-3 Fatty Acids and NCCIH — Diabetes and Dietary Supplements.

B Vitamins, Zinc, Selenium and Antioxidants

Other nutrients have been studied in diabetes, but it is important to differentiate between those with a role in normal physiology, and those that improve outcomes by providing an extra supplement.

Vitamin B12

Vitamin B12 is required for proper nerve function and healthy red blood cell production.

Prolonged use of metformin may cause decreased B12 levels in some individuals. The ADA recommends considering periodic vitamin B12 assessment in people taking metformin long-term, particularly those with anemia or peripheral neuropathy.

This is one example of why it may be important to check for this particular deficiency. It does not mean that everyone on metformin will need to take a B12 supplement.

Vitamins C and E

Antioxidants such as vitamins C and E have been researched for their potential role in reducing oxidative stress and affecting blood glucose levels.

A 2022 systematic review and network meta-analysis examining 178 studies of nutritional supplements for glycemic control in type 2 diabetes reported possible reductions in HbA1c with zinc, vitamin D, omega-3, vitamin C and vitamin E. However, the certainty of the evidence was low.

After lower-quality studies were excluded, only vitamin D showed a statistically significant benefit. Even then, the reported improvements were small and unlikely to make a meaningful clinical difference.

The available evidence therefore does not establish routine vitamin C or E supplementation as an effective treatment for diabetes. High-dose supplementation can also carry health risks.

Zinc and Selenium

Zinc and selenium are important nutrients.

Although zinc and selenium have been investigated for their potential roles in insulin function and oxidative stress, current evidence does not establish that routine supplementation improves diabetes control.

Excessive selenium intake can cause gastrointestinal problems, hair loss, brittle or damaged nails and nervous system effects. High zinc intake can cause nausea and other digestive problems, and prolonged excessive use can interfere with copper absorption.

These nutrients are generally best obtained through a balanced diet. Supplements should be considered when there is a confirmed deficiency or another specific clinical reason, with advice from a healthcare professional.

Supplement Safety, Interactions and Regulation

Safety is an important consideration when looking into supplements for diabetes. Just because an ingredient has been looked at in research, it doesn’t mean that they are effective, reliable or safe in a commercial product.

Why Supplement Quality Matters

Dietary supplements in the United States are regulated differently than prescription drugs.

Unlike prescription drugs, dietary supplements do not undergo FDA approval for safety and effectiveness before marketing.

Manufacturers and distributors are responsible for ensuring that their products meet applicable legal requirements, including safety, labeling and manufacturing standards. The FDA can take enforcement action against products that violate these requirements.

Consumers should be cautious of products that claim to:

Cure diabetes naturally.
Replace insulin or prescribed diabetes medication.
Guarantee a rapid reduction in blood glucose.
Reverse diabetes without medical treatment.
Work for every person regardless of their health condition.

Independent third-party testing may provide information about a supplement’s identity, purity or quality. However, certification does not establish that a product lowers blood glucose or treats diabetes.

Potential Medication Interactions

Some supplements may interact with prescribed medications or affect how they work in the body.

Examples include:

Berberine, which may interact with certain medicines.
Herbal products such as cinnamon, St. John’s wort or aloe vera, which may cause unwanted effects when used with conventional medicines.
Omega-3 supplements, which may interact with medicines that affect blood clotting.
Magnesium supplements, which can interfere with the absorption of certain antibiotics and other medicines.

The likelihood and seriousness of an interaction depend on the supplement, the amount taken, other medicines being used, kidney and liver function and the person’s overall health.

People using insulin or other medicines that can cause hypoglycemia should discuss any proposed supplement with their healthcare professional before using it.

Do not stop or reduce prescribed medication because a supplement appears to be helping. Any changes to diabetes treatment should be discussed with the healthcare professional responsible for prescribing it.

For more detail, read our guide to supplements and diabetes medication interactions.

People Who Need Extra Caution

Professional advice may be needed if you:

Have chronic kidney or liver disease.
Require insulin or take several prescription medications.
Are pregnant, breastfeeding or trying to conceive.
Have had episodes of hypoglycaemia.
Have been diagnosed with a nutrient deficiency or other health problem.
Are considering taking multiple supplements.

If you have diabetes then you may already have an increased risk of kidney disease and some supplements can impact kidney function or build up in the body if kidney function is impaired.

What Do Current Diabetes Guidelines Recommend?

The ADA’s 2026 Standards of Care emphasize individualized diabetes management, including appropriate nutrition, physical activity, behavioral health support and medical treatment.

The ADA recommends assessing supplement use. Routine supplementation with micronutrients such as magnesium or chromium, or herbs and spices such as cinnamon and aloe vera, is not recommended for glycemic benefits.

Universal vitamin D supplementation is also not recommended for people with type 1 or type 2 diabetes who do not have a vitamin D deficiency.

Supplement or vitamin replacement may be appropriate in certain circumstances, such as a confirmed nutritional deficiency, dietary restriction or another specific medical indication.

Periodic vitamin B12 assessment should be considered in people taking metformin long term, particularly those with anemia or peripheral neuropathy. People with additional risk factors may require more frequent monitoring, as advised by their healthcare professional.

This highlights the importance of considering supplement use based on an individual’s nutritional status and medical requirements.

For an overview of diabetes care beyond supplements, see our guide to understanding and managing diabetes.

Frequently Asked Questions

Do diabetes supplements really lower blood sugar?

Some studies have shown improvements in blood glucose levels. However, results are often mixed and the research is often limited.

Current ADA guidelines do not recommend routine micronutrient or herbal supplementation for improving glycemic control. Supplements may still be appropriate when a specific deficiency or medical indication has been identified.

What supplements have been researched the most for type 2 diabetes?

Berberine, magnesium, chromium, cinnamon, vitamin D, psyllium, alpha-lipoic acid and omega-3 fatty acids have been researched.

Evidence varies greatly. Just because it has been researched doesn’t mean it is proven.

Is berberine effective for type 2 diabetes?

Some randomized trials and meta-analyses have shown improvements in fasting blood glucose, post meal blood glucose and HbA1c.

However, results can be difficult to interpret as the quality of research varies, the population studied varies and formulations vary. Berberine can cause side effects and interact with medications.

Berberine should not be used as a replacement for prescribed diabetes medication.

Will magnesium supplements improve insulin sensitivity?

Some studies have shown possible improvement in insulin sensitivity or blood glucose values. There is not enough evidence to recommend magnesium supplements for improving control of diabetes.

However correcting a known magnesium deficiency would be a clinical issue.

Is cinnamon effective to reduce blood glucose?

Some studies have shown a reduction in fasting blood glucose. Evidence is mixed and can depend on the formulation of cinnamon used.

Current ADA guidance does not recommend taking cinnamon supplements for improving glycemic control.

Can vitamin D help prevent type 2 diabetes?

Research has looked at using vitamin D supplements in people with pre-diabetes and those with lower vitamin D levels.

Some analyses have suggested possible benefits in selected groups. However, it is not a proven treatment for preventing diabetes. The ADA does not recommend taking vitamin D supplements universally for those with diabetes who do not have a deficiency.

Can supplements be used instead of metformin or insulin?

No. Supplements should never be used as a replacement for prescribed diabetes medication.

Stopping or reducing insulin, metformin or other prescribed medication can cause poor control of your blood glucose levels and can lead to serious complications.

Are herbal diabetic supplements safe?

No. Natural products can still cause side effects, vary in quality and interact with medications.

Some herbal supplements may not be suitable if you have kidney or liver disease, or if you are pregnant or breastfeeding.

Should I take vitamin B12?

Not everyone will require a B12 supplement. Long-term use of metformin can contribute to lower B12 levels.

The ADA recommends considering periodic vitamin B12 assessment in people taking metformin long-term, particularly those with anemia or peripheral neuropathy. If a deficiency is confirmed or another reason is identified by a healthcare professional then a supplement may be appropriate.

How can I decide if a supplement is something to consider?

Consider why you want to take it. Has the ingredient been researched in people with a similar health condition? What quality of evidence is there? Are there any side effects or interactions? Speak to your doctor or pharmacist about the product.

Don’t be tempted to take it based on advertising, customer reviews or one piece of research.

Key Takeaways

Research on diabetes supplements includes studies of vitamins, minerals, herbal extracts and soluble fiber. However, the evidence varies considerably, and many findings remain uncertain.

Supplements such as berberine, cinnamon, magnesium, chromium and vitamin D have been studied for their possible effects on blood glucose regulation. However, current clinical guidelines do not support their routine use as treatments for hyperglycemia.

Psyllium research has reported improvements in some glucose-related measurements, while alpha-lipoic acid has been investigated for symptoms of diabetic neuropathy. Omega-3 research has examined triglycerides and other cardiovascular markers, as well as glucose-related outcomes. These findings do not establish these supplements as treatments for diabetes.

The most important factors to consider are nutritional need, the quality of the evidence, product safety and possible medication interactions.

Supplements may be appropriate when there is a specific nutritional deficiency or medical indication. They should not replace prescribed diabetes medication, a balanced eating pattern, physical activity or regular medical care.

References

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