Abstract
Vitamin D plays an important role in skeletal muscle function and metabolism. The
aim of this review was A) to discuss the clinical evidence of vitamin D
supplementation either alone or combined with other strategies in the prevention
of sarcopenia in non-sarcopenic individuals and B) to critically discuss the
clinical evidence on the effect of vitamin D combined with other strategies on
muscle strength, mass and function in sarcopenic individuals without vitamin D
deficiency. Sparse clinical data on non-sarcopenic individuals indicate that
vitamin D alone has a subtle beneficial effect on knee extensor strength at
doses 880–1600 IU/day without improving handgrip strength or
muscle mass. When co-administered with other supplements such as protein, mixed
effects appear to prevent the decline of muscle mass, possibly delaying the
onset of sarcopenia in non-sarcopenic individuals, at doses of 800–1,000
IU/day over 6–12 weeks. In sarcopenic individuals, vitamin D
100–1,000 IU/day co-supplementation with protein results in
increased handgrip strength between 9.8–40.5%. However, there is
no strong clinical evidence that vitamin D dosage correlates with changes in
muscle strength or mass. Potential sources of discrepancy among studies are
discussed. Future studies with appropriate experimental design are essential to
dissect the net effect of vitamin D on sarcopenia.
Key words
sarcopenia - skeletal muscle - vitamin D - aging - strength
