Improved HDL Cholesterol through Vitamin D Status Correction Substantially Lowers 10-Year Atherosclerotic Cardiovascular Disease Risk Score in Vitamin D-Deficient Arab Adults

This interventional study aimed to determine whether correcting vitamin D status in deficient Arab adults [25(OH)D <50 nmol/L] improves their 10-year risk of Atherosclerotic Cardiovascular Disease (ASCVD) risk scores. Saudi adults (58 males 62 females) with baseline vitamin D deficiency (<50 nmol/L) were given 50,000 IU cholecalciferol weekly for 2 months, then twice a month, followed by daily 1000 IU until month 6. Fasting blood samples were collected pre- and post-intervention and assessed for glucose, lipids, and 25(OH)D levels. The predicted 10-year ASCVD risk scores were calculated at baseline and after intervention. At baseline, significantly higher 10-year ASCDV risk scores were observed in males than females (9% vs. 3%, p < 0.001). After 6 months, only 21% (25 out of 120) achieved 25(OH)D levels above optimal level (≥75 nmol/L). While modest improvements were seen in glucose and lipid profiles, only HDL cholesterol showed favorable significant changes in all participants, which translated to significantly improved 10-year ASCVD risk scores independent of whether they achieved optimum vitamin D status. Still, those who achieved optimal vitamin D levels had a modestly larger decrease in ASCVD risk scores than those with less optimal 25(OH)D levels (-23% versus -18%) and this improvement was slightly more pronounced in males (-26% versus -10%, or 16% improvement) than females (-47% versus -32%, or 15% improvement). In conclusion, vitamin D status correction significantly enhances HDL cholesterol which prospectively reduces 10-year ASCVD risk as vitamin D levels approach optimum status among adult Arabs with baseline vitamin D deficiency. This improvement appears to be slightly more apparent in males than females.