The American Diabetes Association recommends managing diabetes through diet, lifestyle modifications, and pharmacological therapy.1 Despite lacking substantial evidence, herbal and dietary supplements have become increasingly popular in the diabetic patient population over the years. Although use of dietary supplements is not always recommended, it is best for clinicians to be knowledgeable about the safety and efficacy data surrounding them in order to assist patients who choose to use them. Six popular dietary supplements used in the management of diabetes will be discussed in this article and safety and efficacy data are summarized in Table 1.

Nicotinamide is a vitamin B derivative that is most frequently used in the management of hyperlipidemia.1 Despite compelling evidence of its use in hyperlipidemia, there is a lack of comprehensive data to support its use in all diabetic patients. Several large-scale studies show that nicotinamide may have positive effects after long-term use in type 1 diabetic patients, however additional studies are needed to determine its true safety and efficacy.  

Fenugreek is another dietary supplement that is commonly used by diabetic patients, especially those with limited access to health care.1 Although there are several studies that demonstrate the positive effects of fenugreek on glycemic control, there is a lack of evidence regarding appropriate dosing and formulation. Because of this, additional studies should be conducted prior to recommending it for widespread use.

Vitamin D is another supplement that may be used in the management of diabetes.1 Although research has found an association with suboptimal vitamin D levels and an increased risk of diabetes, it is difficult to determine the exact correlation between the two. Evidence shows that levels of 25-hydroxyvitamin D (25(OH)-D) of >30 ng/mL are associated with a 60% higher insulin sensitivity compared to levels of <10 ng/mL. Although studies have shown that vitamin D may decrease the progression of type 2 diabetes, there is a lack of substantial evidence regarding its safety and efficacy in diabetic patients. Because of this, it is difficult to formulate well-defined recommendations on the appropriate use of vitamin D in this population and additional studies are required.

Chromium is found in various foods such as meat, cereals, and nuts, and can also be used as a supplement in diabetic patients.1 Research has found that patients with type 2 diabetes have 33 to >50% lower chromium levels than the general population.  Various studies have analyzed supplementation with chromium and results indicate that this trace element may provide blood glucose-lowering benefits in diabetic patients. Additional studies should be completed to fully analyze long-term benefits and establish true safety and efficacy of chromium.