title: Vitamin D deficiency, muscle function, and falls in elderly people.
abstract: An inadequate serum vitamin D status is commonly seen in elderly people as the result of various risk factors interacting in this population. Apart from the well-known effects on bone metabolism, this condition is also associated with muscle weakness, predominantly of the proximal muscle groups. Muscle weakness below a certain threshold affects functional ability and mobility, which puts an elderly person at increased risk of falling and fractures. Therefore, we wanted to determine the rationale behind vitamin D supplementation in elderly people to preserve and possibly improve muscle strength and subsequently functional ability. From experimental studies it was found that vitamin D metabolites directly influence muscle cell maturation and functioning through a vitamin D receptor. Vitamin D supplementation in vitamin D-deficient, elderly people improved muscle strength, walking distance, and functional ability and resulted in a reduction in falls and non-vertebral fractures. In healthy elderly people, muscle strength declined with age and was not prevented by vitamin D supplementation. In contrast,severe comorbidity might affect muscle strength in such a way that restoration of a good vitamin D status has a limited effect on functional ability. Additional research is needed to further clarify to what extent vitamin D supplementation can preserve muscle strength and prevent falls and fractures in elderly people.
authors.affiliation: Department of Geriatric Medicine, University Medical Center, Utrecht, Netherlands. h.c.j.p.janssen@azu.nl
authors.forename: Hennie C J P
authors.initials: HC
authors.lastname: Janssen
authors.forename: Monique M
authors.initials: MM
authors.lastname: Samson
authors.forename: Harald J J
authors.initials: HJ
authors.lastname: Verhaar
mesh_terms: D000058:Accidental Falls / Q000517:prevention & control*; D000328:Adult; D000368:Aged; D015519:Bone Density; D005260:Female; D005853:Geriatrics; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000502:physiology; D014807:Vitamin D / Q000378:metabolism / Q000627:therapeutic use*; D014808:Vitamin D Deficiency / Q000150:complications* / Q000503:physiopathology
chemical_list: D014807:Vitamin D