Effect of Vitamin D on Endothelial Function: A Randomized, Double-Blind, Placebo-Controlled Trial

Area of Science:

• Cardiovascular Health
• Endocrinology
• Nutritional Science

Background:

• Low 25-hydroxyvitamin D (25[OH]D) levels are linked to hypertension risk and endothelial dysfunction in nonhypertensive individuals.
• The impact of vitamin D supplementation on endothelial function in this population remains under-explored.

Purpose of the Study:

• To investigate the effect of ergocalciferol supplementation on endothelial function in nonhypertensive, overweight, or obese individuals with vitamin D deficiency.

Main Methods:

• A randomized, double-blind, placebo-controlled trial was conducted.
• Participants received weekly ergocalciferol (50,000 units) or placebo for 8 weeks.
• Endothelial-dependent vasodilation (EDV) was measured via brachial artery ultrasound.

Main Results:

• Mean 25[OH]D levels increased significantly in the vitamin D group (14.9 to 30.3 ng/ml) but not in the placebo group.
• No significant change in EDV was observed in either the vitamin D group (P=0.78) or the placebo group (P=0.17).
• The difference in EDV change between groups was not statistically significant (P=0.35).

Conclusions:

• Vitamin D repletion with ergocalciferol did not improve endothelial function in overweight/obese nonhypertensive individuals with vitamin D deficiency.
• The findings suggest that vitamin D supplementation may not be an effective strategy for enhancing endothelial function in this specific demographic.