[Concentration of 25-hydroxyvitamin D in postmenopausal women with low bone mineral density].

OBJECTIVES: This study was designed to determine mean serum concentrations of 25-hydroxyvitamin D (25OHD) in postmenopausal women with low bone mineral density (BMD), to find the cutoff of parathormone (PTH) elevation, and to evaluate the correlation 25OHD with BMD, biochemical parameters and vertebral fracture presence.

METHODS: Transversal study, with collection of 25OHD and PTH, and determination of DMO and column radiograph.

RESULTS: A high incidence of inadequate serum concentrations of 25OHD (68.3%) was found and 8% of secondary hyperparathyreoidism. No significant differences were found between 25OHD serum concentrations and the evaluated parameters, except for PTH, which showed a negative association. The established cutoff was 61.5 nmol/L.

CONCLUSIONS: The elevated incidence of hipovitaminosis D in elderly women with low BMD suggests that a systematic evaluation of 25OHD serum concentrations must be done for this population.The use of 61.5 nmol/L as a cutoff is recommended until the realization of an epidemiologic study that represents all Rio de Janeiro city (RJ, Brazil).