Effects of Vitamin D on Muscle Mass Regulation: Potential Treatment in Patients with Sarcopenia
Keywords:aging, mTOR, sarcopenia, vitamin D
Many studies have revealed that vitamin D is required in the cellular metabolism of skeletal muscles. It acts in the genomic pathway, particularly in the mTOR signalling pathway, namely IGF-I-Akt-FOXO pathway. Vitamin D also acts in the ATP-dependent ubiquitin-proteasome pathway, a major proteolytic pathway, affecting mitochondrial function. In older adults, vitamin D deficiency is quite common leading to decrease in muscle mass and strength and increase in frailty incidence. Sarcopenia enhances the risk of physical limitation, reduces life quality and independence and increases mortality. Because of its burden, the potential treatment is required to improve the muscle strenght. Based on previous studies, vitamin D supplementation has advantageous effects on sarcopenia. These effects include increase in muscle strength and suppression in the process of muscle atrophy. However, the precise role of vitamin D supplementation in preventing and treating sarcopenia is still being explored. Further interventional investigations are required to prove the effectiveness of vitamin D supplementation on skeletal muscle. Moreover, determining the optimum level of this vitamin to preserve muscle mass and strength in older adults requires further investigation.