Vitamin D Supplementation and Impact on Skeletal Muscle Function in Cell and Animal Models and an Aging Population: What Do We Know So Far?

Abstract

Aging is associated with impairment in skeletal muscle mass and contractile function, predisposing to fat mass gain, insulin resistance and diabetes. The impact of Vitamin D (VitD) supplementation on skeletal muscle mass and function in older adults is still controversial. The aim of this review was to summarize data from randomized clinical trials, animal dietary intervention and cell studies in order to clarify current knowledge on the effects of VitD on skeletal muscle as reported for these three types of experiments. A structured research of the literature in Medline via PubMed was conducted and a total of 43 articles were analysed (cells n = 18, animals n = 13 and humans n = 13). The results as described by these key studies demonstrate, overall, at cell and animal levels, that VitD treatments had positive effects on the development of muscle fibres in cells in culture, skeletal muscle force and hypertrophy. Vitamin D supplementation appears to regulate not only lipid and mitochondrial muscle metabolism but also to have a direct effect on glucose metabolism and insulin driven signalling. However, considering the human perspective, results revealed a predominance of null effects of the vitamin on muscle in the ageing population, but experimental design may have influenced the study outcome in humans. Well-designed long duration double-blinded trials, standardised VitD dosing regimen, larger sample sized studies and standardised measurements may be helpful tools to accurately determine results and compare to those observed in cells and animal dietary intervention models.

How Soon Do Metabolic Alterations and Oxidative Distress Precede the Reduction of Muscle Mass and Strength in Wistar Rats?

“…metabolism, leading to increased protein consumption and increased anaerobic metabolism (Abdel-Mageid et al 2018). These ndings are related to the reduction of peripheral sensitivity to insulin, where with advancing age metabolic changes precede structural changes, and even loss of muscle mass, strength and/or function(Brunetta et al 2020;Romeu Montenegro et al 2021). In this sense, our ndings reinforce those changes in energy metabolism occur long before any structural and macroscopic changes in the muscle are noticed.…”

Vitamin D is Positively Associated with Bone Mineral Density Muscle Mass and Negatively with Insulin Resistance in Senile Diabetes Mellitus

“…In vitro assays revealed positive influences of vitamin D-based therapy on muscle cell hypertrophy, muscle fibers, and muscle strength in cultured cells. A prior study pointed out that vitamin D supplementation can regulate lipid and mitochondrial muscle metabolism and can also directly impact glucose metabolism and insulin-driven signal transduction [ 23 ]. For patients with senile T2DM, serum vitamin D level deficiency contributes to the decrease of muscle mass and function and would result in the decrease of lower limb muscle mass [ 24 ].…”

The Key Role of Nutritional Elements on Sport Rehabilitation and the Effects of Nutrients Intake

“…In vitro studies have shown that vitamin D receptors (VDR) are expressed in the muscle stem cells depicting muscle regeneration after injury [44]. A recent review revealed that vitamin D supplementation from any source had no effect on muscle mass in elders, even though it benefitted cultured muscle fibers cells in vitro [45].…”