Bone turnover markers and vitamin D status in postmenopausal Turkish women

The aim of this study was to examine some biochemical markers of bone metabolism such as C-telopeptide of type 1 collagen (CTx), procollagen I N-peptide (PINP), 25 hydroxy vitamin D [25(OH)D], parathormone (PTH), and alkaline phosphatase (total- and bone-ALP) in postmenopausal Turkish women, and to evaluate the influence of dietary factors on these parameters. This cross-sectional study comprised 70 postmenopausal and 25 premenopausal subjects from a similar socio-economical status. The postmenopausal group was further stratified with regard to vitamin plus calcium supplementation. A fasting blood sample was obtained for the biochemical analysis of bone markers. Ca, P, tALP, and CTx levels were significantly higher in postmenopausal women free of supplementation than those in premenopausal period; whereas 25(OH)D concentrations were below the reference value in both groups. Supplementations of vitamin and calcium resulted in significantly lower levels of PINP in the postmenopausal group (p = 0.017). A significant association was found between plasma 25(OH)D level and frequency of fish consumption. Dietary strategies to fortify calcium and vitamin D intake should be considered to decrease the complications due to D hypovitaminosis after the onset of menopause.