title: Vitamin D and muscle function in the elderly: the elixir of youth?
abstract: OBJECTIVE
  Circumstantial evidence suggests that vitamin D deficiency may contribute to age-related changes in skeletal muscle. This review discusses recent clinical trials examining effects of vitamin D on muscle function in the elderly, and poses the important question: can vitamin D reverse muscle ageing?
  
  
  RESULTS
  Observational studies report an association between vitamin D and muscle atrophy/weakness in elderly subjects. Interventional studies suggest that frail, elderly subjects may benefit from vitamin D supplementation by displaying reduced falls, improved muscle function and increased muscle fibre size. However, meta-analyses do not report convincing effects of vitamin D in the elderly. This may be because of multiple factors including lack of standardized endpoints for muscle function, variable study design and different doses of vitamin D supplementation amongst these studies. The evidence base is therefore inconsistent.
  
  
  CONCLUSIONS
  Vitamin D deficiency may exacerbate ageing of skeletal muscle. However, current evidence that vitamin D supplementation reverses age-related muscle dysfunction is equivocal and does not justify stringent vitamin D targets in the elderly. Until these issues are clarified, the safest option is to aim for conservative vitamin D targets that are sufficient for normal calcium homeostasis.
authors.affiliation: aGarvan Institute of Medical Research bFaculty of Medicine, University of Sydney, Sydney, NSW, Australia.
authors.forename: Christian M
authors.initials: CM
authors.lastname: Girgis
mesh_terms: D000368:Aged; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D016330:Frail Elderly; D006801:Humans; D015201:Meta-Analysis as Topic; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000502:physiology*; D009133:Muscular Atrophy / Q000097:blood / Q000188:drug therapy / Q000209:etiology; D064887:Observational Studies as Topic; D016032:Randomized Controlled Trials as Topic; D014807:Vitamin D / Q000008:administration & dosage / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications / Q000188:drug therapy
chemical_list: D014807:Vitamin D