Vitamin D status, including serum levels and sun exposure are associated or correlated with bone mass measurements diagnosis, and bone density of the spine

Background: Osteoporosis is a health complication worldwide, especially in developing countries. The prevalence was reported to be 18.3% globally. While the effect of biochemical factors on fracture risk/odds has been documented, the association/correlation between serum 25(OH)D levels, vitamin D dietary intake, and sun exposure with bone mineral density (BMD) remains controversial. This study aimed to evaluate the association and correlation between vitamin D status, including serum levels, dietary intakes, and sun exposure with BMD. We hypothesized that vitamin D-related factors would have different correlations/associations with BMD, which would help better evaluate future studies’ results. Methods: A total of 186 individuals were included in this study (winter 2020). BMD was measured by Dual-energy X-ray absorptiometry. Blood serum levels of 25(OH)D, phosphorus, calcium, parathyroid hormone (PTH), and calcitonin were tested using standard lab tests. Valid and reliable questionnaires were used for sun exposure assessment and dietary intakes. Results: There was a significant protective association between spine BMD (classifications, two groups) (OR = 0.69, 95%CI: 0.50–0.94; p-value = 0.023), BMD diagnosis (classifications, two groups) (OR = 0. 69, 95%CI: 0.49–0.87; p-value = 0.036) and sun exposure. There was a significant and moderate correlation between Spine measurements (Spine BMD: Pearson correlation coefficient = 0.302, p-value = 0.046; Spine T-score: Pearson correlation coefficient = 0.322, p-value = 0.033, Spine Z-score: Pearson correlation coefficient = 0.328, p-value = 0.030) and serum 25(OH)D. In addition, participants with osteopenia and osteoporosis significantly consume a higher amount of soluble fiber than the normal BMD group. There was no significant correlation between vitamin D intake and BMD. Conclusion: In conclusion, serum 25(OH)D levels and sun exposure are correlated and associated with BMD. However, prospective studies are needed to investigate the association between dietary vitamin D intake and BMD.