Are the serum 25-hydroxyvitamin D concentrations in winter associated with forearm bone mineral density in healthy elderly Japanese women?

The objective of this study was to investigate whether the serum 25-hydroxyvitamin D (25[OH]D) concentrations in winter are associated with the BMD in elderly Japanese women. The subjects were 117 healthy elderly Japanese women. Serum 25(OH)D concentrations were determined by high-performance liquid chromatography. Forearm BMD in the non-dominant arm was measured by dual-energy X-ray :absorptiometry (DXA) using a DTX-200 Osteometer. The mean age of the subjects was 66.1:(SD 6.5) years (range: 46-80). The average 25(OH)D concentration was 59.1 nmol/L (SD 16.1), and five of the subjects had low 25(OH)D concentrations (< 30 nmol/L). Forearm BMD decreased linearly with age (r(2) = 0.275). There was no linear association between the serum 25(OH)D concentrations and the forearm BMD (p = 0.9483). Multiple regression analysis did not reveal ally association between the two (p = 0.5318) when age (p < 0.0001, r(2) = 0.271) and weight (p < 0.0001, r(2) = 0.153) were taken into account. Our cross-sectional. study failed to reveal any association between the serum 25(OH)D concentrations and the forearm BMD in elderly Japanese;women, suggesting that 25(OH)D does not play an important role in the determination of BMD. A follow-np study should be conducted to confirm the results of our cross-sectional study.