Vitamin D deficiency and its relationship with bone mineral density among postmenopausal women living in the tropics

OBJECTIVE: To determine vitamin D (25OHD) status and its relationship with bone mineral density (BMD) in 93 postmenopausal women. SUBJECTS AND METHODS: Patients were distributed in two groups: Group 1 - 51 to 65 years (n = 45) and Group 2 - 66 to 84 years (n = 48); 25OHD and PTH serum were analyzed and a DXA scan of the lumbar spine (LS) and femoral neck (FN) were taken. RESULTS: Mean +/- SD of serum 25OHD levels were 80.6 +/- 43.3 nmol/L (Group 1) and 63.7 +/- 27.6 nmol/L (Group 2); 24% had 25OHD levels < 25 nmol/L and 43.7% < 50 nmol/L. The prevalence of vitamin D deficiency at the 62.5 nmol/L cutoff increased significantly with age. Patients with hypovitaminosis D had a lower BMD at the FN (0.738 +/- 0.102 vs. 0.793 +/- 0.115 g/cm, p = 0.03) and had been postmenopausal for longer (21.0 +/- 8.4 vs. 16.2 +/- 8.4 years, p = 0.01). CONCLUSION: We found a high prevalence of hypovitaminosis D in postmenopausal women. Age, years elapsed since menopause and low BMD in the FN were associated with deficiency.