VITAMIN-D-RECEPTOR GENOTYPES AND CHANGES OF BONE-DENSITY IN PHYSICALLY ACTIVE GERMAN WOMEN WITH HIGH-CALCIUM INTAKE

Polymorphisms at the vitamin D receptor (VDR) gene have been reported to mediate important differences in bone mineral density (BMD) and bon e metabolism. In this longitudinal study we examined the relationships between VDR genotypes and bone metabolism, changes in BMD and changes in ultrasound transmission velocity in a population of healthy unrela ted German women. The study population comprised 50 physically active women (aged 43.3 to 62.8 years, 14 premenopausal, 36 postmenopausal) w ith a daily calcium intake of (mean +/- SD) 1045 +/- 338 mg, who had e arlier participated in a longitudinal study on the association of phys ical activity and bone density and bone turnover. Each participant was genotyped for the BsmI polymorphism at the VDR gene locus. Markers of bone turnover (alkaline phosphatase, osteocalcin, procollagen type I C-terminal propeptide, collagen type I C-terminal telopeptide, tartrat e-resistant acid phosphatase) were measured at baseline. BMD (determin ed by peripheral quantitative computed tomography at the distal radius ) and ultrasound transmission velocity through bone (at calcaneus, pat ella and thumb) were analysed at baseline and 15 months later. The gen otypic groups did not differ significantly (P > 0.05) in any of the pa rameters determined at baseline. Neither were there any differences be tween these groups in the changes of BMD or ultrasound transmission ve locity during the study period. Thus, we conclude that in physically a ctive German women with a relatively high calcium intake the impact of VDR genotypic polymorphisms on bone density, bone metabolism and chan ges in bone density may be of limited importance.