A positive association of vitamin D deficiency and sarcopenia in 50 year old women, but not men.

BACKGROUND & AIMS: Sarcopenia, loss of muscle mass and function, is one of the major risk factors for metabolic diseases and vitamin D is also positively associated with their prevalence. We examined whether vitamin D deficiency was positively associated with sarcopenia in a gender-specific manner in adults aged ≥50 years, independent of other covariates and possible confounders, including body composition, blood tests, including serum parathyroid hormone (PTH) levels, dietary intake, and hormone replacement therapy in women.

METHODS: This cross-sectional study included 2258 men and 3005 women aged ≥50 years who participated in the 2009-2010 Korean National Health and Nutrition Examination Survey. Sarcopenia was defined as appendicular skeletal muscle mass/body weight <2 standard deviations below gender-specific means for young adults. Vitamin D status was represented by serum 25-hydroxyvitamin D (25-OH-D) levels. Adjusted odds ratios for having sarcopenia were calculated according to vitamin D status, while controlling for covariates that affect vitamin D status and body composition using logistic regression analysis with incorporating the sample weights for the complex sample design of the survey.

RESULTS: Sarcopenia showed a strong inverse association with serum 25-OH-D levels in women, but not men, independent of other covariates and possible confounders. Sarcopenia was negatively associated with dietary intakes of energy, protein, and carbohydrates in both men and women, but walking and exercise showed no significant relationship with sarcopenic status. Sarcopenic status was significantly associated with serum total 25-OH-D and cholesterol levels only in women and with serum PTH levels only in men. The risk of sarcopenia was increased, by 1.46-fold, by lowering serum 25-OH-D by 10 ng/mL only in women.

CONCLUSIONS: Serum 25-OH-D levels were a negative modulator of sarcopenia only in women aged ≥50 years in a Korean population.