维生素D与骨骼肌

Vitamin D and skeletal muscle

维生素D是调节钙磷代谢和维持骨骼健康的重要激素前体,然而近年来大量临床研究结果显示,维生素D缺乏可出现肌力下降、跌倒风险增加,而补充维生素D能够帮助增强肌力、减少跌倒机会从而降低骨折风险。但维生素D如何作用于骨骼肌,并不十分清楚,动物和细胞实验研究发现维生素D对骨骼肌的作用可能包括直接作用和间接作用,即直接通过激活肌细胞内的维生素D受体或其他因子和间接通过调节血钙和血磷水平。如能阐明维生素D在骨骼肌细胞内的作用机制,将有助于指导维生素D的临床应用,从而预防跌倒以降低骨质疏松性骨折风险。

Vitamin D is an important hormone precursor regulating calcium and phosphate homeostasis and keeping bone healthy. However, a large number of clinical trials in recent years have shown that vitamin D deficiency decreases muscle strength and increases risk of fall and vitamin D supplementation enhances muscle strength and reduces risk of fall, and therefore reduces risk of fractures. However, the mechanism by which vitamin D works on skeletal muscle remains unclear. The research in the literature has indicated that the effect of vitamin D on skeletal muscle may be direct and/or indirect. The direct effect is probably via activation of the vitamin D receptor （VDR） or unknown factors in muscle cells, and the indirect effect is probably via regulating serum calcium and phosphorus levels. Elucidating the molecular mechanism by which vitamin D works on skeletal muscle may help guide the clinical application of vitamin D in muscle weakness and ultimately formulate strategies to reduce risk of osteoporostic fractures.