Effect of a single dose of Vitamin D3 on postprandial arterial stiffness and inflammation in Vitamin D-deficient women

Context: Cholecalciferol (Vitamin D3) improves vascular function and inflammation, potentially providing an explanation for the proposed cardiovascular protection of Vitamin D. Objective: We investigated whether cholecalciferol supplementation reduces postprandial arterial dysfunction and inflammation. Design: Randomized, 1:1, double-blind trial. Setting: Diabetes and Vascular Center, Franciscus Gasthuis, Rotterdam, The Netherlands. Patients: Twenty-four healthy, premenopausal, overweight or obese, Vitamin D-deficient women. Interventions: A single high (300,000 IU) or low dose (75,000 IU) of cholecalciferol. Main Outcome Measures: The effect of low-and high-dose cholecalciferol on postprandial leukocyte activation markers, pulse wave velocity (PWV), and augmentation index (AIx) during an oral fat loading test, expressed as area under the curve (AUC). Results: High-and low-dose supplementation increased Vitamin D by 163% 6 134% (P ,0.001) and 66%659% (P,0.001), respectively. Monocyte CD11b-AUC slightly increased after low but not high dose (6% 6 2%, P = 0.012, and 4% 6 1%, P = 0.339, respectively). There were no significant effects on postprandial PWV or AIx by high-or low-dose Vitamin D. Fasting complement component 3 (C3) levels decreased by 5.9% (P = 0.004) in the high-dose group and by 4.0% (P = 0.018) in the low-dose group. Conclusion: A single dose of Vitamin D does not seem to reduce arterial stiffness and leukocyte activation in overweight, Vitamin D-deficient women. Vitamin D may decrease fasting C3. Possibly, higher Vitamin D concentrations may be needed to decrease inflammation and improve vascular function in overweight or obese Vitamin D-deficientwomen.