25-hydroxyvitamin D status and change in physical performance and strength in older adults: the Health, Aging, and Body Composition Study.
Houston DK, Tooze JA, Neiberg RH, Hausman DB, Johnson MA, Cauley JA, Bauer DC, Cawthon PM, Shea MK, Schwartz GG, Williamson JD, Tylavsky FA, Visser M, Simonsick EM, Harris TB, Kritchevsky SB. 25-hydroxyvitamin D status and change in physical performance and strength in older adults: the Health, Aging, and Body Composition Study. Am J Epidemiol. 2012 Dec 01; 176(11):1025-34.