Association Between Serum Vitamin D Levels and Visceral Adipose Tissue in Older Adults in Iran: A Cross-Sectional Study From the Amirkola Health and Aging Project

The relationship between vitamin D status and visceral adiposity among older adults remains unclear. This study aimed to investigate the association between serum vitamin D levels and visceral adipose tissue (VAT) among older Iranian adults. This cross-sectional study included older adults aged ≥ 60 years from the Amirkola Health and Aging Project. Serum 25-hydroxyvitamin D levels were measured by enzyme-linked immunosorbent assay. VAT was assessed using dual-energy X-ray absorptiometry. Furthermore, the relationship between vitamin D and VAT was examined through multiple linear regression analysis, adjusting for potential confounders. Of the 600 participants, 345 (57.5%) were males and 255 (42.5%) were females. Their mean age was 68.90 ± 6.97 years, and the mean vitamin D level was 60.50 ± 39.45 ng/mL. Serum vitamin D levels showed a weak negative association with VAT mass (β = -0.062, p = 0.012). In both sexes, VAT mass predictors followed a similar pattern. Body mass index (BMI; β = 0.811, p < 0.001) was identified as a strong predictor, while diabetes status exhibited a positive association with VAT mass (β = 0.078, p = 0.002). Serum vitamin D levels appear to have a weak inverse relationship with visceral adiposity in older Iranian adults. BMI was the most robust predictor of VAT. Further longitudinal research is needed to clarify the causal relationship between vitamin D status and visceral adiposity among older adults.