Potential of Vitamin D and l-Cysteine Co-supplementation to Downregulate Mammalian Target of Rapamycin: A Novel Therapeutic Approach to Diabetes.

Diabetes, a metabolic disease associated with an increased health care burden and mortality, is currently on the rise. Both upregulation of the mammalian target of rapamycin (mTOR) and decreased levels of vitamin D (VD) and l-cysteine (LC) have been associated with diabetes. The overactivation of mTOR leads to insulin desensitization and metabolic dysfunction including uncontrolled hyperglycemia. This review summarizes various studies that have shown an inhibitory effect of VD or LC on mTOR activity. Findings from preclinical studies suggest that optimizing the VD and LC status in patients with diabetes can result in mTOR suppression, which has the potential to protect these individuals from microvascular and macrovascular complications while enhancing the regulation of their blood glucose. Given this information, finding ways to suppress mTOR signaling and also increasing VD and LC status is a possible therapeutic approach that might aid patients with diabetes. Future clinical trials are needed to investigate whether VD and LC co-supplementation can successfully downregulate mTOR and can be used as adjuvant therapy in patients with diabetes.