Supplements for Diabetes Mellitus: A Review of the Literature

The primary approach to controlling diabetes involves diet and lifestyle modification combined with pharmacologic interventions. Patients who are interested in exploring dietary supplements in the management of diabetes may have questions about which supplement to choose and whether any issues will arise with their current medication regimen. After reading this review, the pharmacist should be able to identify supplements that may provide benefit to improve diabetes management, understand what potential harm to the patient may occur, and be able to assist the patient in choosing high-quality supplements. This review will focus on the safety and efficacy data surrounding nicotinamide, ginseng, fenugreek, vitamin D, chromium, and cinnamon. These supplements are commonly listed in general circulation periodicals with claims to improve blood sugar management. Efficacy data showed a modest decrease in fasting plasma glucose of −0.96 mmol/dL (−17.29 mg/dL) for fenugreek and −24.59 mg/dL for cinnamon. It remains to be seen whether supplementation with these products can affect outcomes such as morbidity and mortality. Despite many studies being available, the majority lack uniformity across multiple dimensions, including varying participant characteristics, inconsistent formulations of supplement and dose, and differing study durations. This, coupled with variation in quality and purity of commercially available products, prevents universal recommendation for use in diabetes management.