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Supplements for Diabetes

Nina Ghamrawi, MS, RD, CDE
January 13, 2022

There’s a huge industry around supplements to help you ‘cure’ diseases and ‘flush out’ toxins. But many supplement companies market their products without solid evidence to support their claims. And because diabetes affects the majority of our population, many people are not only curious, but sometimes desperate to try any supplement that just might give them relief. But don’t believe everything that you hear. In this article, we’ll uncover some of the Diabetes supplements on the market and the research around them.

The following supplements, per NIH, may be appropriate for some patients. There are no natural or manufactured supplements that have been proven with either a strong correlation or a lot of research to lower blood sugars. The following is a list of supplements that you may have heard about, a summary of the major research studies on them, and their potential side effects.

Supplement What it might do Side effects
Alpha lipoic acid Reduce the risk of complications:
• Diabetic macular edema (an eye condition that can cause vision loss)
• Diabetic neuropathy (nerve damage caused by diabetes)
Can cause stomach problems in high doses.
Chromium May improve blood sugar control slightly in some people who have inadequate dietary chromium intake May cause stomach pain and bloating, kidney damage, muscular problems, and skin reactions in large doses.
Herbal Supplements:
• Cinnamon
• Bitter melon
• Fenugreek
• Ginseng
• Milk thistle
• Sweet potato
• St John’s wort
• Prickly pear cactus
• Aloe
These may help lower glucose.

There is no reliable evidence to support any glucose effects.
Varying unwanted side effects, including sleepiness, flatulence or diarrhea, or bitter mouth taste.
Not enough magnesium in the diet may increase the risk of developing diabetes. However there is not enough evidence to support taking magnesium to improve glucose for patients with Diabetes.

If you are unsure, if you need a supplement or not, try eating more foods rich in magnesium: bran cereal, certain seeds and nuts, and spinach are a few.
Large doses can cause diarrhea and abdominal cramping.

Very large doses (over 5,000mg/day) can be deadly
Fish oil Fish oil has not been shown to lower blood glucose levels or reduce diabetes risk. However, plenty of benefits exist for the heart:
• Lowers LDL
• Lowers triglycerides
• Raises HDL
May cause a fishy aftertaste, bad breath, gas, nausea, vomiting or diarrhea; may interact with some blood-thinning medications
Selenium Does not reduce diabetes risk or blood glucose. Long-term intake can cause hair and nail loss, gastrointestinal symptoms, and nervous system abnormalities.
Vitamin C “…a 2017 research review of 22 studies with 937 participants found weak evidence that vitamin C helped with blood sugar in people with type 2 diabetes when they took it for longer than 30 days.”(NIH) There are no adverse effects from taking vitamin C supplements.
Vitamin D Low blood vitamin D is associated with an increased risk of developing: type 2 diabetes, metabolic syndrome, or insulin resistance. However, taking vitamin D doesn’t prevent or improve Diabetes.

Supplementing with Vitamin D, however may help to improve mood, and reduce depression.
Too much Vitamin D can cause nausea, constipation, weakness, kidney damage, disorientation, and problems with your heart rhythm.

You’re unlikely to get too much vitamin D from food or the sun.


While there are no supplements for Diabetes proven to surely help lower risk, nutrition and physical activity are important parts of a healthy lifestyle for people with diabetes. Eating well and being physically active can help you

  • Keep your blood glucose level, blood pressure, and cholesterol in your target ranges
  • Lose weight or stay at a healthy weight
  • Prevent or delay diabetes problems
  • Improve mood
  • Have more energy

Living a healthful lifestyle may also help force diabetes into remission for those that are borderline and newly diagnosed. As always, besides diet and exercise, taking your prescribed diabetes medications is a sure way to keep your glucose in control. Talk with your doctor if you are wondering about a medication adjustment, or are thinking about starting any supplements. Also speak with your Health Coach or Dietitian to ensure we are doing everything that we can with the diet before starting a supplement.