The Impact of Serum 25-Hydroxyvitamin D on Bone Mineral Density at Different Skeletal Sites: A Multivariate Analysis...

Vitamin D is essential for bone health, but its effects on bone mineral density (BMD) may exhibit regional variations. This study aims to ascertain whether a consistent relationship exists between serum vitamin D and BMD at various bone sites. Participants were recruited from the UK Biobank, a large prospective cohort study. Serum 25-hydroxyvitamin D levels were measured at baseline (2006-2010), and BMD at the lumbar, pelvis, spine, femur, and arm were evaluated via DXA. A multivariate regression analysis was employed to examine the relationship between serum 25-hydroxyvitamin D and BMD at five sites simultaneously. This retrospective cohort study included 20,131 participants. The fully adjusted model revealed that a 1 nmol/L increase in serum 25-hydroxyvitamin D was associated with a 0.24, 0.38, 0.37, 0.28, and 0.20 mg/cm² higher BMD at the spine, lumbar, pelvis, femur, and arm, respectively. The multivariate regression demonstrated that serum vitamin D strongly correlated with the BMD at the lumbar and pelvis regions, followed by the femur, spine, and arm. The associations were significantly different by gender, with smaller impacts observed in females compared to males at the pelvis, femur, and arm. Our study indicated a positive correlation between serum 25-hydroxyvitamin D and BMD in middle-aged and older individuals. The impacts varied between different bone regions, with the trunk bone region having a greater impact than the radius region. These findings emphasize the importance of monitoring serum 25-hydroxyvitamin D levels to optimize bone health.