25(OH) Vitamin D Is Associated with Greater Muscle Strength in Healthy Men and Women

GRIMALDI, ADAM S.1; PARKER, BETH A.1; CAPIZZI, JEFFREY A.1; CLARKSON, PRISCILLA M.2; PESCATELLO, LINDA S.3; WHITE, MICHAEL C.3; THOMPSON, PAUL D.1

Medicine & Science in Sports & Exercise: January 2013 - Volume 45 - Issue 1 - p 157–162
doi: 10.1249/MSS.0b013e31826c9a78
Applied Sciences

Purpose: The purpose of the study was to examine the relation between serum 25-hydroxy vitamin D (25(OH)D) levels and muscle strength in 419 healthy men and women over a broad age range (20–76 yr).

Methods: Isometric and isokinetic strength of the arms and legs was measured using computerized dynamometry, and its relation to vitamin D was tested in multivariate models controlling for age, gender, resting HR, systolic blood pressure, diastolic blood pressure, body mass index, maximal oxygen uptake (V˙O2max,), physical activity counts, and season of vitamin D measurement.

Results: Vitamin D was significantly associated with arm and leg muscle strength when controlling for age and gender. When controlling for other covariates listed previously, vitamin D remained directly related to both isometric and isokinetic arm strength but only to isometric leg strength.

Conclusion: These data suggest that there may be a differential effect of vitamin D on upper and lower body strength. The mechanism for this difference remains unclear but could be related to differences in androgenic effects or to differences in vitamin D receptor expression. Our study supports a direct relation between vitamin D and muscle strength and suggests that vitamin D supplementation be evaluated to determine whether it is an effective therapy to preserve muscle strength in adults.

1Division of Cardiology, Henry Low Heart Center, Hartford Hospital, Hartford, CT; 2University of Massachusetts, Amherst, MA; and 3University of Connecticut, Storrs, CT

Address for correspondence: Paul D. Thompson, M.D., Division of Cardiology, Henry Low Heart Center, Hartford Hospital, Hartford, CT 06102; E-mail: pthomps@harthosp.org.

Submitted for publication February 2012.

Accepted for publication July 2012.

©2013The American College of Sports Medicine