This study investigates the relationship between vitamin D status and cardiometabolic risk factors in a large, community-based sample of 3,890 nondiabetic individuals from the Framingham Heart Study. The primary objectives were to examine the association of serum 25-hydroxyvitamin D (25(OH)D) concentrations with adiposity measures and insulin resistance, and to determine whether these associations were independent of physical activity and vitamin D intake. Key findings include: 1. **Vitamin D and Adiposity**: 25(OH)D was inversely associated with subcutaneous and visceral adipose tissue (SAT and VAT) volumes, even among lean individuals. The prevalence of vitamin D deficiency was significantly higher in individuals with high VAT compared to those with low VAT. 2. **Vitamin D and Insulin Resistance**: The association between 25(OH)D and insulin resistance measures was attenuated after adjusting for VAT, suggesting that excess visceral adiposity may contribute to the observed relationship between vitamin D and metabolic traits. 3. **Clinical Implications**: The study highlights the importance of adiposity, particularly visceral adiposity, in understanding the relationship between vitamin D status and cardiometabolic risk. These findings have implications for the prevention and management of chronic diseases associated with vitamin D deficiency. The study underscores the need for further research to explore the mechanisms by which adiposity promotes vitamin D deficiency and to understand the clinical implications of these findings.This study investigates the relationship between vitamin D status and cardiometabolic risk factors in a large, community-based sample of 3,890 nondiabetic individuals from the Framingham Heart Study. The primary objectives were to examine the association of serum 25-hydroxyvitamin D (25(OH)D) concentrations with adiposity measures and insulin resistance, and to determine whether these associations were independent of physical activity and vitamin D intake. Key findings include: 1. **Vitamin D and Adiposity**: 25(OH)D was inversely associated with subcutaneous and visceral adipose tissue (SAT and VAT) volumes, even among lean individuals. The prevalence of vitamin D deficiency was significantly higher in individuals with high VAT compared to those with low VAT. 2. **Vitamin D and Insulin Resistance**: The association between 25(OH)D and insulin resistance measures was attenuated after adjusting for VAT, suggesting that excess visceral adiposity may contribute to the observed relationship between vitamin D and metabolic traits. 3. **Clinical Implications**: The study highlights the importance of adiposity, particularly visceral adiposity, in understanding the relationship between vitamin D status and cardiometabolic risk. These findings have implications for the prevention and management of chronic diseases associated with vitamin D deficiency. The study underscores the need for further research to explore the mechanisms by which adiposity promotes vitamin D deficiency and to understand the clinical implications of these findings.