Influence of vitamin D levels on bone mineral density and osteoporosis

BACKGROUND AND OBJECTIVES: The effects of vitamin D on bone mass remain to be understood. This study was conducted with the objective of evaluating the influence of 25-hydroxyvitamin D (25OHD) levels on bone mineral density (BMD) among Saudi nationals. DESIGN AND SETTING: Cross-sectional study carried out at university hospital from 1 February 2008 to 31 May 2008. SUBJECTS AND METHODS: Healthy Saudi men and women in the peak bone mass (PBM) age group and those aged >= 50 years were recruited from the outpatient department of King Fahd University Hospital, Al Khobar, Saudi Arabia, between February 1, 2008, and May 31, 2008. Patient age and sex were documented, and body mass index was calculated. Hematological, biochemical, and serum 25OHD tests were performed. BMD was determined by dual-energy x-ray absorptiometry of the upper femur and lumbar spine. Patients were divided into three groups, based on their 25OHD level. RESULTS: Data from 400 patients were analyzed. Among individuals with a normal 25OHD level, 50% of women and 7% of men in the PBM age group and 26.4% of women and 49.2% of men aged >= 50 years had low bone mass. In patients with 25OHD insufficiency, 84.2% of women and 88.9% of men in the PBM age group and 83.3% of women and 80% of men aged >= 50 years had low bone mass. Results for patients with 25OHD deficiency revealed that none of the men and women in the PBM age group or >= 50 years old had normal BMD. Significant positive correlations between 25OHD level and BMD and significant negative correlations with parathyroid hormone were shown in most of the groups. CONCLUSIONS: This study showed that the vitamin D level significantly influences BMD reading among Saudi individuals. Evaluation and treatment of hypovitaminosis D should be considered during management of low bone mass.