Table of Contents Author Guidelines Submit a Manuscript
International Journal of Endocrinology
Volume 2014, Article ID 487463, 5 pages
http://dx.doi.org/10.1155/2014/487463
Clinical Study

Serum 25-OH Vitamin D in relation to Bone Mineral Density and Bone Turnover

1Endocrinology and Diabetes, Universitá Campus Bio-Medico di Roma, Via Alvaro del Portillo 21, 00128 Rome, Italy
2Dipartimento di Medicina Interna e Specialistica (DIMIS), Università di Palermo, Via del Vespro 129, 90127 Palermo, Italy
3Endocrine Unit, Department of Medical and Biological Sciences, Universitá di Palermo, Via delle Croci 47, 90139 Palermo, Italy

Received 5 January 2014; Accepted 22 June 2014; Published 7 July 2014

Academic Editor: Reina Armamento-Villareal

Copyright © 2014 Nicola Napoli et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

It is unclear which vitamin D status is optimal for bone health. In this study, we aimed to assess cutoffs of 25-hydroxyvitamin D (25OHD) derived by the literature (20, 25, or 30 ng/mL) in relation to bone turnover and bone mineral density (BMD). Serum 25OHD, PTH, osteocalcin, bone alkaline phosphatase, and C-telopeptide were measured in 274 consecutive postmenopausal women. BMD of the lumbar spine (L1–L4) and of femoral neck were also evaluated. 50 patients had normal BMD, while 124 had osteopenia and 100 had osteoporosis. 37.6%, 56.2%, and 70.8% subjects had serum 25OHD lower than 20, 25, or 30 ng/mL, respectively. No differences in bone turnover markers were found when comparing patients with low 25OHD defined according to the different cutoffs. However, a cutoff of 25 ng/mL appeared to differentiate better than a cutoff of 30 ng/mL in those subjects with reduced femoral neck BMD. The PTH plateau occurred at 25OHD levels of 26–30 ng/mL. In conclusion, vitamin D deficiency is common in Sicilian postmenopausal women and it may be associated with low BMD and increased bone turnover markers. Further studies are needed to better define the right cutoff for normal vitamin D levels in postmenopausal women.