Skeletal muscle loss and impaired muscle regeneration are increasingly recognized as complications associated with diabetes and persistent hyperglycemia. A 2026 study published in Nutrition & Diabetes explored whether vitamin C, a potent antioxidant, could counteract these effects. Researchers first used Drosophila larvae exposed to a high-sugar diet to model hyperglycemia. Compared with controls, these larvae showed growth retardation, impaired insulin responses, increased triglyceride levels, and smaller skeletal muscle fibers. The affected muscles also demonstrated reduced expression of MEF2 and myosin heavy chain (MHC):; important markers of muscle development, along with increased expression of CG11658, the Drosophila homolog of Atrogin-1, and FOXO target genes associated with muscle protein breakdown.

Vitamin C supplementation partially improved growth and food intake while reducing several hyperglycemia-associated abnormalities. At the molecular level, it reduced oxidative stress and restored expression of Tet (ten-eleven-translocation), an epigenetic regulator involved in cellular differentiation. Importantly, the beneficial effects were also observed in complementary models: vitamin C promoted myogenic differentiation of C2C12 muscle cells exposed to high-sugar conditions and enhanced skeletal muscle regeneration following injury in streptozotocin-induced hyperglycemic mice. Together, the findings suggest that oxidative stress, altered muscle differentiation, and disrupted regulatory pathways may contribute to muscle deterioration during hyperglycemia, while vitamin C may help counter some of these changes. However, these results are currently based on laboratory and animal models; clinical studies are needed to establish whether vitamin C supplementation can protect or restore skeletal muscle in people with diabetes.