Navigating a health condition like diabetes can feel complex, to say the least. Navigating nutrient deficiencies associated with diabetes is just one of the many facets of learning to care for yourself, whether this is a new journey or one you’ve been on for years.

From vitamins that support insulin function to minerals that aid in blood sugar management, there is plenty of research showing a potential positive impact that vitamins and minerals can have on overall health and diabetes management.

Impacts of Supplements on Diabetes: What to Know About Vitamins and Minerals with Diabetes

While vitamins and minerals can play a powerful role in your overall health, specific vitamins and minerals can also help manage diabetes. But how do you know what you need, or how do you determine if something may cause more harm than good?

Because our bodies are all different, the best thing to do is to work with a Registered Dietitian who can personalize nutrition and supplement recommendations based on you, your lifestyle, and your individual needs. They can also help inform you of potential risks associated with supplements for diabetes management, to ensure that you don’t mistakenly take something that fixes one issue while unintentionally causing another.

Micronutrients can play a positive role in your health and wellness, but it’s important to know how they may interact with different medications in addition to other potential side effects and reactions. Here is an overview of the ways a few key vitamins and minerals can impact diabetes.

Berberine

Berberine is a naturally occurring alkaloid that is found in plants. However, it could also have powerful benefits for those with diabetes. 

Research has shown that berberine can help lower blood glucose in a similar manner to standard medications, like metformin.¹ This appears to work by improving insulin sensitivity, reducing glucose production in the liver, and influencing gut microbiota, helping create more stable blood sugar levels.

Berberine may also help improve lipid profiles, including cholesterol and triglycerides.²

In patients with Type 2 diabetes, one study linked berberine with “significant decreases” in hemoglobin A1c, fasting blood glucose, postprandial blood glucose, and plasma triglycerides.³ 

Important Notes

While some supplements may be less risky to begin taking independently, it’s extra important to talk with your dietitian and/or healthcare provider before taking berberine.

Potential Side Effects & Reactions	Constipation, gastrointestinal upset, or low blood sugar if combined with other diabetes medications May react with metformin or insulin (causing hypoglycemia), blood pressure medications, and CYP enzyme substrates, which can affect how drugs are metabolized Should be avoided in pregnancy and while breastfeeding, due to the risk of kernicterus
Important Notes & Considerations	More research is needed to understand the long-term safety of taking berberine as a supplement to help manage diabetes. Effectiveness may decrease after 90 days and in those over age 60.⁴ Taking it with meals may help reduce blood sugar spikes and improve tolerance.
Dose	500 mg, taken 2 to 3 times per day (1,000–1,500 mg/day)* Berberine has a short half-life of 4-6 hours, so it’s often recommended to split the dose throughout the day to help with blood sugar stability. *Some people start with 250 mg once or twice daily, then gradually increase as they see how it impacts them. A higher dose does not necessarily make it more effective, and may increase the risk of side effects.

Inositol

Inositol is one way that sugar naturally takes form in our bodies, and can be found both in food as a supplement and as a supplement on its own.⁵

Inositol has been linked with helping improve insulin sensitivity and supporting a metabolic profile (through lowering triglycerides in modest amounts, alongside encouraging healthy LDL and HDL levels).

As a supplement, inositol’s benefits have primarily been studied in regard to gestational diabetes and Polycystic Ovarian Syndrome (PCOS), among other conditions.

A 2020 meta-analysis found that in those with PCOS, a 40:1 ratio of myo-inositol to D-Chiro inositol greatly improved fasting insulin levels, helping improve blood sugars.⁶

Another small study evaluating those treated with myoinositol found they had significantly lower fasting plasma glucose, post-dinner glucose, and insulin requirements both in the 2nd and in the 3rd trimesters.⁷

In short, this supplement may help improve insulin sensitivity along with a balanced metabolic profile, but more research is needed to understand its true impact on individuals with diabetes.

Potential Side Effects & Reactions	May cause abdominal pain, diarrhea, dizziness, fatigue, headache, nausea
Important Notes & Considerations	None of note
Dose	1-4 g daily* *Some studies have evaluated inositol use up to 18 g⁸

Vitamin B12

Vitamin B12 plays an important role in a wide range of body processes, including cell metabolism, nerve function, and the formation of red blood cells.⁹ Metformin, a common medication to help manage diabetes, has been known to decrease the absorption of this essential vitamin and can cause a deficiency over time.¹⁰ In fact, anywhere from 6-30% of patients on metformin have been found to have a vitamin B12 deficiency.¹¹

Vitamin B12 deficiency can cause anemia, fatigue, muscle weakness, intestinal issues, mood disturbances, and nerve damage. 

Some research has also shown that in cases of metformin-induced B12 deficiencies, calcium supplementation can help with B12 absorption.¹²

Potential Side Effects & Reactions	Can cause diarrhea, fatigue, headache, nausea and vomiting, tingling in the hands and feet, or weakness
Important Notes & Considerations	B12 can either be taken orally (pill form) or be administered as an injection. While it’s generally safe to take more B12 than the recommended daily amount, it’s important to be aware of the potential health risks and to consult with a professional.
Dose	Most adults need 2.4 mcg daily.* *Some professionals may recommend a higher dose if there is a true deficiency.¹³

Zinc

Zinc plays an important role in a number of body processes, including growth and development, wound healing, easing inflammation, and more. On the flip side, zinc deficiency can cause chronic diarrhea, skin rashes, trouble with wound healing, behavioral issues, and growth delays.¹⁴

Zinc also plays a critical role in the synthesis, storage, and secretion by pancreatic beta cells—meaning, a deficiency can harm insulin production and release. This may contribute to insulin resistance.¹⁵

A meta-analysis evaluating diabetes prevention and management found that zinc supplementation improved fasting glucose, postprandial glucose, fasting insulin, homeostasis model assessment for insulin resistance, glycated hemoglobin, and high-sensitivity C-reactive proteins.¹⁶

Animal studies also showed evidence that zinc supplementation was linked with enhanced insulin sensitivity and antioxidant status.¹⁷

Many individuals with Type 2 diabetes have zinc deficiency due to decreased absorption in the digestive tract and increased urinary excretion with hypoglycemia and metabolic disturbances, so supplementation may be helpful.¹⁸

Important Note

While there can be some great benefits of zinc supplementation in those with diabetes — especially in those who are deficient — be sure to talk to a healthcare provider before starting supplementation.

Potential Side Effects & Reactions	Excess zinc can cause copper deficiency, gastrointestinal upset, or impaired immune function
Important Notes & Considerations	Long-term high doses can interfere with copper/iron absorption It’s best to take with food to avoid stomach upset
Dose	15–30 mg daily elemental zinc (usually as zinc sulfate, gluconate, or acetate)

Magnesium

Magnesium plays a highly important role in helping the body adjust blood glucose levels. It also supports other body functions, including immune system function, maintaining a steady heartbeat, and enhancing bone strength.¹⁹ Magnesium deficiencies can cause symptoms including hyperexcitability, muscle weakness, and sleepiness.

Magnesium deficits and increased urinary magnesium excretion are not uncommon in both individuals with Type 2 Diabetes and those with insulin resistance.²⁰

There are several different forms of magnesium that may have different benefits for individuals with diabetes.

Magnesium Citrate

Magnesium citrate was linked with improving both fasting glucose and insulin sensitivity in one study of non-diabetic patients with insulin resistance, and in another of patients with diabetic neuropathy.²¹ ²²

Magnesium Glycinate (Bisglycinate)

This form of magnesium is gentler and may not cause as many stomach problems and upset for individuals compared to other forms of magnesium.²³

Magnesium Taurate

Magnesium taurate is essentially a combination of magnesium and taurine, an amino acid. When taken as the combined form, magnesium taurate can improve insulin resistance, lower blood pressure, help prevent arrhythmias, and more.²⁴

However, it’s crucial to note that because taurine can decrease blood sugar levels, it can cause critically low blood sugar in individuals who take insulin, so be sure to consult your doctor before starting supplementation.²⁵

Potential Side Effects & Reactions	Symptoms of magnesium toxicity can include confusion, difficulty breathing, dizziness, facial flushing, low blood pressure, irregular heartbeat, and more. Can make antibiotics less effective, can interact with proton pump inhibitors (PPIs), osteoporosis medications, and more.
Important Notes & Considerations	Taking over 350 mg may cause stomach upset, and can cause toxicity if taken in high levels (5,000 mg+)
Dose	250–400 mg day

Vitamin D

This essential vitamin plays a powerful role in our health and well-being. Specifically, it keeps our bones healthy, helps our bodies absorb calcium, supports our parathyroid glands, and much, much more.

It may be difficult to tell if you’re deficient in vitamin D, however, some signs may include bone pain, muscle cramps or weakness, changes in mood (feeling down), or a lack of energy.

Vitamin D (or lack thereof) has been associated with insulin resistance, insulin sensitivity, lipid metabolism, glucose intolerance, metabolic syndrome, and more.

In individuals with Type 2 diabetes, vitamin D administration was linked with improvements to glucose metabolism and a lowered risk of metabolic syndrome.²⁶

Another study suggested that vitamin D supplementation may improve glucose and insulin metabolism, albeit in nondiabetic individuals.²⁷

Potential Side Effects & Reactions	Vitamin D toxicity can include confusion, constipation, frequent urination, nausea, weakness, and more. May react with steroids, medications containing aluminum, anticonvulsants, orlistat, steroids, and more
Important Notes & Considerations	As a fat-soluble vitamin, Vitamin D will absorb best when taken with a meal 10–30 minutes of sunlight several times a week can also provide significant amounts of vitamin D, although factors like location, skin type, and more can impact this
Dose	General Population: 400-800 IU daily Vitamin D-Deficient Individuals: 1000-4,000 IU daily²⁸

Ensure Safe Supplements for Diabetes with a Dietitian

These are just a few supplements that can help with diabetes management and overall health.

When you are changing your supplement routine, whether there is a deficiency or not, be sure to discuss this with a Registered Dietitian. They will help ensure your supplement choices are safe, effective and tailored to your specific needs. They can also help you learn how to get specific nutrients from food sources in a way that supports your overall health. 

At Life Cycle Nutrition, we are experts in navigating the complexities of nutrition, including the nuances of vitamins and minerals for diabetes that come with managing the condition. Schedule an appointment to support your health and individual journey today.

 

Works Cited

 

1. Want, Haoran, Chen Zhu, Ying Ying, Lingyu Luo, Deqiang Huang, and Zhijun Luo. 2017. “Metformin and berberine, two versatile drugs in treatment of common metabolic diseases.” Oncotarget 9, no. 11 (September): 10135-10146. https://doi.org/10.18632/oncotarget.20807.
2. Cao, Changfu, and Meiqing Su. 2019. “Effects of berberine on glucose-lipid metabolism, inflammatory factors and insulin resistance in patients with metabolic syndrome.” Experimental and Therapeutic Medicine 17, no. 4 (February): 3009-3014. https://doi.org/10.3892/etm.2019.7295.
3. Yin, Jun, Huili Xing, and Jianping Ye. 2008. “Efficacy of Berberine in Patients with Type 2 Diabetes.” Metabolism 57, no. 5 (May): 712-717. https://doi.org/10.1016/j.metabol.2008.01.013.
4. Liang, Yaping, Xiaojia Xu, Mingjuan Yin, Yan Zhang, Lingfeng Huang, Ruoling Chen, and Jindong Ni. 2019. “Effects of berberine on blood glucose in patients with type 2 diabetes mellitus: a systematic literature review and a meta-analysis.” Endocrine Journal 66, no. 1 (January): 51-63. https://doi.org/10.1507/endocrj.EJ18-0109.
5. “Inositol: Benefits & Side Effects.” 2023. Cleveland Clinic. https://my.clevelandclinic.org/health/drugs/25173-inositol.
6. Pintaudi, Basilo, Giacoma Di Veste, and Matteo Bonomo. 2016. “The Effectiveness of Myo-Inositol and D-Chiro Inositol Treatment in Type 2 Diabetes.” International Journal of Endocrinology, no. 1 (October). https://doi.org/10.1155/2016/9132052.
7. Guarnotta, Valentina, Gianluca Cuva, Miaria P. Imbergamo, and Carla Giordano. 2022. “Myoinositol supplementation in the treatment of gestational diabetes mellitus: effects on glycaemic control and maternal-foetal outcomes.” BMC Pregnancy and Childbirth 22 (June). https://doi.org/10.1186/s12884-022-04852-3.
8. Meixner, Makayla. 2023. “Inositol: Benefits, Side Effects and Dosage.” Healthline. https://www.healthline.com/nutrition/inositol#other-benefits.
9. Mayo Clinic Staff. 2024. “Vitamin B-12.” Mayo Clinic. https://www.mayoclinic.org/drugs-supplements-vitamin-b12/art-20363663.
10. Hurley-Kim, Keri, Chuong H. Vu, Nhat M. Dao, Sarah McBane, Joyce Lee, and Aryana Sepassi. 2023. “Effect of Metformin Use on Vitamin B12 Deficiency Over Time (EMBER): A Real-World Evidence Database Study.” AACE Endocrine Practice 29, no. 11 (August): 862-867. https://doi.org/10.1016/j.eprac.2023.06.013.
11. Kim, Jiwoon, Chul W. Ahn, Sungsoon Fang, Hye S. Lee, and Jong S. Park. 2019. “Association between metformin dose and vitamin B12 deficiency in patients with type 2 diabetes.” Medicine 98, no. 46 (November). https://doi.org/10.1097/MD.0000000000017918.
12. Bauman, W A, S. Shaw, E. Jayatilleke, A M Spungen, and V. Herbert. 2000. “Increased intake of calcium reverses vitamin B12 malabsorption induced by metformin.” Diabetes Care 23, no. 9 (September): 1227-1231. https://doi.org/10.2337/diacare.23.9.1227.
13. Kim et al., “Association between Metformin Dose,” Medicine.
14. Richter, Amy. 2018. “Zinc: Benefits, Deficiency, Food Sources and Side Effects.” Healthline. https://www.healthline.com/nutrition/zinc.
15. Li, Yang V. August. “Zinc and insulin in pancreatic beta-cells.” Endocrine 45, no. 2 (24): 178-189. https://doi.org/10.1007/s12020-013-0032-x.
16. Wang, Xinhui, Wenhui Wu, Wanru Zheng, Xuexian Fang, Liyun Chen, Lothar Rink, Junxia Min, and Fudi Wang. 2019. “https://www.sciencedirect.com/science/article/pii/S0002916522011546.” The American Journal of Clinical Nutrition 110 (1): 76-90. https://doi.org/10.1093/ajcn/nqz041.
17. Ranasinghe, Priyanga, Shehani Pigera, Priyadarshani Galappatthy, Prasad Katulanda, and Godwin R. Constantine. 2015. “Zinc and diabetes mellitus: understanding molecular mechanisms and clinical implications.” DARU Journal of Pharmaceutical Sciences 23, no. 1 (September). https://doi.org/10.1186/s40199-015-0127-4.
18. Ahmad, Rahnuma, Ronald Shaju, Azeddine Atfi, and Mohammed S. Razzaque. 2024. “Zinc and Diabetes: A Connection between Micronutrient and Metabolism.” Cells 13, no. 16 (August). https://doi.org/10.3390/cells13161359.
19. Manetti, Stefania. 2023. “Magnesium in diet.” MedlinePlus. https://medlineplus.gov/ency/article/002423.htm.
20. National Institutes of Health Office of Dietary Supplements. 2022. “Magnesium – Health Professional Fact Sheet.” NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/.
21. Mooren, F C, K. Krüger, K. Völker, S W Golf, M. Wadepuhl, and A. Kraus. 2011. “Oral magnesium supplementation reduces insulin resistance in non-diabetic subjects – a double-blind, placebo-controlled, randomized trial.” Diabetes, Obesity and Metabolism 13, no. 2 (March): 281-284. https://doi.org/10.1111/j.1463-1326.2010.01332.x.
22. Halawa, Nihal, Tamer W. Elsaid, Lamia M. El Wakeel, and May A. Shawki. 2023. “Impact of magnesium supplementation on clinical outcome and disease progression of patients with diabetic nephropathy: a prospective randomized trial.” Therapeutic Advances in Chronic Disease, (December). https://doi.org/10.1177/20406223231214641.
23. Meacham, Jared. 2025. “Magnesium glycinate: Benefits, side effects, dosage, and more.” Medical News Today. https://www.medicalnewstoday.com/articles/315372.
24. Houston, Mark. 2011. “The Role of Magnesium in Hypertension and Cardiovascular Disease.” The Journal of Clinical Hypertension 13, no. 11 (September): 843-847. https://doi.org/10.1111/j.1751-7176.2011.00538.x.
25. Dorwart, Laura. 2024. “Magnesium Taurate: Benefits, Uses, Side Effects, and More.” Health. https://www.health.com/magnesium-taurate-8546934#citation-6.
26. Argano, Christiano, Luigi Mirarchi, Simona Amodeo, Valentina Orlando, Alessandra Torres, and Salvatore Corrao. 2023. “The Role of Vitamin D and Its Molecular Bases in Insulin Resistance, Diabetes, Metabolic Syndrome, and Cardiovascular Disease: State of the Art.” International Journal of Molecular Sciences 24, no. 20 (October). https://doi.org/10.3390/ijms242015485.
27. Tang, Huilin, Deming Li, Yufeng Li, Xi Zhang, Yiqing Song, and Xinli Li. 2018. “Effects of Vitamin D Supplementation on Glucose and Insulin Homeostasis and Incident Diabetes among Nondiabetic Adults: A Meta-Analysis of Randomized Controlled Trials.” International Journal of Endocrinology 2018, no. 1 (December). https://doi.org/10.1155/2018/7908764.
28. Raman, Ryan. 2024. “What Vitamin D Dosage Is Best?” Healthline. https://www.healthline.com/nutrition/vitamin-d-dosage.