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

Abstract

BACKGROUND:

In nonhypertensive individuals, lower levels of 25-hydroxyvitamin D (25[OH]D) have been associated with an increased risk of hypertension, and vitamin D deficiency has been associated with endothelial dysfunction in such individuals. However, the effect of vitamin D supplementation on endothelial dysfunction in nonhypertensive individuals has not been examined in a rigorous fashion.

METHODS:

In this randomized, double-blind, placebo-controlled trial of nonhypertensive, nondiabetic overweight, or obese individuals with vitamin D deficiency (body mass index ≥25 and 25[OH]D ≤ 20 ng/ml), we assigned subjects to receive either ergocalciferol (50,000 units) or matching placebo, once a week for 8 weeks. Our primary outcome was endothelial-dependent vasodilation (EDV) measured by brachial artery ultrasound at baseline and 8 weeks postrandomization.

RESULTS:

By the end of the trial, 46 and 47 participants were allocated to receive ergocalciferol and placebo, respectively. Mean 25(OH)D levels increased from 14.9 to 30.3 in the vitamin D group and 14.4 to 17.4 in the placebo. EDV did not change significantly with either vitamin D repletion (from 6.3 ± 3.6% at baseline to 6.1 ± 4.6% at 8 weeks; P value = 0.78) or placebo (7.9 ± 4.7% to 6.8 ± 4.7%; P = 0.17). The treatment effect P value (comparing the 8-week change with ergocalciferol to the change with placebo) was 0.35.

CONCLUSIONS:

In this randomized, double-blind, placebo-controlled trial, there was no improvement in endothelial function (measured as EDV) after repletion of vitamin D in overweight/obese nonhypertensive individuals.

• Authors: Lea Borgi, Ciaran McMullan, Ann Wohlhueter, Gary C Curhan, Naomi D Fisher, John P Forman
• Journal: American journal of hypertension (Am J Hypertens) Vol. 30 Issue 2 Pg. 124-129 (Feb 2017) ISSN: 1941-7225 [Electronic] United States
• PMID: 28077419 (Publication Type: Journal Article, Randomized Controlled Trial)
• Copyright: © American Journal of Hypertension, Ltd 2016. All rights reserved. For Permissions, please email: [email protected].

Chemical References

• Vitamins
• Vitamin D
• 25-hydroxyvitamin D

Topics

• Administration, Oral
• Adult
• Brachial Artery (diagnostic imaging, drug effects, physiopathology)
• Dietary Supplements
• Dose-Response Relationship, Drug
• Double-Blind Method
• Drug Administration Schedule
• Endothelium, Vascular (drug effects, physiopathology)
• Female
• Follow-Up Studies
• Humans
• Male
• Radioimmunoassay
• Time Factors
• Treatment Outcome
• Ultrasonography
• Vasodilation (drug effects, physiology)
• Vitamin D (administration & dosage, analogs & derivatives, blood)
• Vitamin D Deficiency (blood, drug therapy, physiopathology)
• Vitamins (administration & dosage)