Determination of serum 25-hydroxyvitamin D3 levels in early postmenopausal Iranian women: relationship with bone mineral density

Serum levels of 25-hydroxyvitamin D3 (25-OHD3) and bone mineral density (BMD) were determined in 73 selected, early postmenopausal women referred to the Bone Densitometry Center, Loghman-Hakim Hospital, Tehran, Iran. The relationship between them was also assessed. 25-OHD3 levels were measured using high-performance liquid chromatography. BMD was measured with dual-energy X-ray absorptiometry of the lumbar spine and proximal femur regions. 25-OHD3 levels ranged from 3.8 to 64.0 ng/mL (mean ± SD: 17.1 ± 11.3). Twenty-six subjects (36%) were vitamin D-deficient (<12 ng/mL). In the lumbar spine (L2–4) BMD measurements, 28 subjects (38%) were normal (T score > −1), 26 (36%) were osteopenic (T ≤ −1 to >−2.5), and 19 (26%) were osteoporotic (T< −2.5). In the hip (total) BMD measurements, 41 subjects (56.1%) were normal, 31 (42.5%) were osteopenic, and 1 (1.4%) was osteoporotic. There was a significant correlation between spine BMD (Z score) and 25-OHD3 (r = 0.23, p< 0.05), but the correlation was not significant for hip BMD. It was concluded that vitamin D deficiency was evident in early postmenopausal Iranian women, and serum 25-OHD3 was weakly correlated with spine BMD, which may have physiological significance.