Relationship between bone mineral density, bone turnover markers and homocysteine, folate and vitamin B12 levels in postmenopausal women

We aimed to investigate whether levels of homocysteine (Hcy), folate, and vitamin B12 are related to bone turnover markers and bone mineral density (BMD) in postmenopausal women. One hundred and twenty postmenopausal women were divided into three groups: osteoporotic, osteopenic and normal, according to the BMD measurements. The age, weight, body mass index (BMI), years since menopause (YSM), gravidity, parity, bone turnover markers [type I collagen C-telopeptides (CTx) and bone-specific alkaline phosphatase (BAP)], serum Hcy, parathyroid hormone (PTH), vitamin B12, folate, calcium and magnesium levels were compared with each other. Twenty-five women had osteoporotic, 42 women had osteopenic, and 53 had normal BMD values. After adjusting for confounding factors, serum Hcy levels were significantly higher in osteoporotic women [adj OR = 38.95 (1.474-1029.88) p = 0.02]. The age, YSM, PTH, CTx and BAP levels were related to serum Hcy in all women (beta = 0.523, p = 0.0001; beta = 0.446, p = 0.001; beta = 0.295, p = 0.005; beta = 0.239, p = 0.026; beta = 0.451, p = 0.001, respectively). Our data showed that vitamin B12, folate and Hcy levels were not related with BMD in postmenopausal women. We think that one of the underlying mechanisms of increased Hcy levels and osteoporosis may be a mechanistic link which cannot detected by BMD or biochemical markers.