Serum 25-hydroxyvitamin D and intact parathyroid hormone influences muscle outcomes in children and adolescents

• Published in: Journal of bone and mineral research 2018-08, Vol.33 (11), p.1940-1947
• Main Authors: Wright, Christian S, Laing, Emma M, Pollock, Norman K, Hausman, Dorothy B, Weaver, Connie M, Martin, Berdine R, McCabe, George P, Peacock, Munro, Warden, Stuart J, Gallant, Kathleen Hill, Lewis, Richard D
• Format: Article
• Language: English
• ISSN: 0884-0431; 1523-4681
• DOI: 10.1002/jbmr.3550

Increases in 25-hydroxyvitamin D concentrations are shown to improve muscle strength in adults; however, data in pediatric populations are scant and equivocal. In this ancillary study of a larger-scale, multi-sited, double-blind, randomized, placebo-controlled vitamin D intervention in US children and adolescents, we examined the associations between changes in vitamin D metabolites and changes in muscle mass, strength, and composition following 12-weeks of vitamin D3 supplementation. Healthy male and female, black and white children and adolescents between the ages of 9-13 years old from two US states (Georgia 34°N and Indiana 40°N) were enrolled in the study and randomly assigned to receive an oral vitamin D3 dose of 0, 400, 1,000, 2,000 or 4,000 IU/d for 12 weeks between the winter months of 2009 to 2011 (N=324). Analyses of covariance, partial correlations, and regression analyses of baseline and 12-week changes (post-baseline) in vitamin D metabolites (serum 25(OH)D, 1,25(OH) 2 D, intact parathyroid hormone (iPTH)) and outcomes of muscle mass, strength, and composition (total body fat-free soft tissue (FFST), handgrip strength, forearm and calf muscle cross-sectional area (MCSA), muscle density, and intermuscular adipose tissue (IMAT)) were assessed. Serum 25(OH)D and 1,25(OH) 2 D, but not iPTH, increased over time, as did fat mass, FFST, forearm and calf MCSA, forearm IMAT, and handgrip strength (p