Vitamin D and BMD

ZURICH, Switzerland—–Among men and women, serum 25-hydroxyvitamin D [25(OH)D] status seemed to be the dominant predictor of bone mass density (BMD) relative to calcium intake (J Bone Miner Res. 2009;24:935-942) (DOI:10.1359/jbmr.081242). To study the relative importance of dietary calcium intake and 25(OH)D status in regard to hip BMD, 4,958 community-dwelling women and 5,003 men 20 years or older in age from the U.S. NHANES III population-based survey were studied. Calcium supplement users and individuals with a prior radius or hip fracture were excluded. Researchers calculated standardized means for BMD by quartiles of sex-specific calcium intake for three 25(OH)D categories among men and women, separately controlling for other important predictors of BMD. A higher calcium intake was significantly associated with higher BMD only for women with 25(OH)D status less than 50 nM, whereas calcium intake beyond the upper end of the lowest quartile (more than 566 mg/d) was not significantly associated with BMD at 25(OH)D concentrations more than 50 nM. Among men, there was no significant association between a higher calcium intake beyond the upper end of the lowest quartile (626 mg/d) and BMD within all 25(OH)D categories. Among both sexes, BMD increased stepwise and significantly with higher 25(OH)D concentrations. Only women with 25(OH)D concentrations less than 50 nM seem to benefit from a higher calcium intake.