Association between serum 25-hydroxyvitamin D levels and cardiometabolic index among overweight/obese U.S. adults: A cross-sectional study

Obesity is a major driver of cardiovascular disease (CVD) risk, with the cardiometabolic index (CMI) serving as a novel indicator. While vitamin D's potential protective role against CVD is recognized, its precise dose-response relationship with CMI in high-risk overweight/obese individuals remains unclear. This study aimed to systematically evaluate the association between serum 25-hydroxyvitamin D (25(OH)D) levels and CMI in overweight/obese U.S. adults and characterize its dose-response pattern. A cross-sectional analysis was conducted using data from the National Health and Nutrition Examination Survey 2009 to 2018, including 6597 overweight/obese participants aged 18 to 64 years. Serum 25(OH)D levels were categorized into 3 groups: sufficient (≥75 nmol/L), insufficient (50-74 nmol/L), and deficient (