Context: There has been a resurgence of vitamin D deficiency among infants, toddlers and adolescents in the United Kingdom. Myopathy is an important clinical symptom of vitamin D deficiency, yet it has not been widely studied.
Objective: To investigate the relationship of baseline serum 25-hydroxyvitamin D concentration (25(OH)D) and parathyroid hormone (PTH) with muscle power and force
Design: Cross sectional study
Setting: Community based in a secondary school
Participants: Ninety-nine post-menarchal 12–14 year old females
Main outcome measures: Jumping mechanography to measure muscle power, velocity, jump height and Esslinger Fitness Index (EFI) from a two legged counter movement jump and force from multiple one-legged hops. Body height, weight and serum concentrations of 25(OH)D, PTH and calcium (Ca) were measured.
Median serum 25(OH)D concentration was 21.3 nmol/L, range 2.5 – 88.5 nmol/L and PTH 3.7 pmol/L (range 0.47 – 26.2 pmol/L).
After correction for weight using a quadratic function there was a positive relationship between 25(OH)D and jump velocity (p=0.002), jump height (p = 0.005), power (p = 0.003), Esslinger Fitness Index (p=0.003) and force (p = 0.05).
There was a negative effect of PTH upon jump velocity (p = 0.04).
Conclusions: From these data we conclude that vitamin D was significantly associated with muscle power and force in adolescent girls.
Source: Journal of Clinical Endocrinology & Metabolism, Feb 2009. E-pub. PMID: 19033372, by Ward KA, Das G, Berry JL, Roberts SA, Rawer R, Adams JE, Mughal Z. Imaging Science and Biomedical Engineering, University of Manchester; Central Manchester Primary Care Trust, Longsight Health Centre; Vitamin D Research Group, Medicine, University of Manchester, Manchester Royal Infirmary; Health Methodology Research Group, University of Manchester; Novotec Medical GmBH, Pforzheim, Germany; Department of Paediatric Medicine, Saint Mary's Hospital for Women & Children, Central Manchester & Manchester Children's Hospitals NHS Trust, Manchester, UK. [E-mail: Kate.Ward@mrc-hnr.cam.ac.uk ]