Vitamin D improves endothelial function in patients with Type 2 diabetes mellitus and low vitamin D levels

J. A. Sugden, J. I. Davies, M. D. Witham, A. D. Morris, A. D. Struthers

    Research output: Contribution to journalArticle

    403 Citations (Scopus)

    Abstract

    Aims To test whether a single large dose of vitamin D2 can improve endothelial function in patients with Type 2 diabetes mellitus and low serum 25-hydroxyvitamin D levels.

    Methods Double-blind, parallel group, placebo-controlled randomized trial. A single dose of 100 000 IU vitamin D2 or placebo was administered to patients with Type 2 diabetes over the winter, when levels of circulating 25-hydroxyvitamin D were likely to be lowest. Patients were enrolled if their baseline 25-hydroxyvitamin D level was < 50 nmol/l. Endothelial function and blood pressure were measured and fasting blood samples were taken at baseline and 8 weeks after administration of vitamin D.

    Results Forty-nine per cent of subjects screened had 25-hydroxyvitamin D levels < 50 nmol/l. Thirty-four subjects completed the study, with a mean age of 64 years and a baseline 25-hydroxyvitamin D level of 38.3 nmol/l. Vitamin D supplementation increased 25-hydroxyvitamin D levels by 15.3 nmol/l relative to placebo and significantly improved flow mediated vasodilatation (FMD) of the brachial artery by 2.3%. The improvement in FMD remained significant after adjusting for changes in blood pressure. Vitamin D supplementation significantly decreased systolic blood pressure by 14 mmHg compared with placebo; this did not correlate with change in FMD.

    Conclusions Vitamin D insufficiency is common in patients with Type 2 diabetes during winter in Scotland. A single large dose of oral vitamin D2 improves endothelial function in patients with Type 2 diabetes and vitamin D insufficiency.

    Original languageEnglish
    Pages (from-to)320-325
    Number of pages6
    JournalDiabetic Medicine
    Volume25
    Issue number3
    DOIs
    Publication statusPublished - Mar 2008

    Keywords

    • blood pressure
    • endothelial function
    • vitamin D
    • CARDIOVASCULAR-DISEASE
    • BLOOD-PRESSURE
    • 1,25-DIHYDROXYVITAMIN D-3
    • D SUPPLEMENTATION
    • HEART-DISEASE
    • PREVENTION
    • EXPRESSION
    • CALCIUM
    • RISK
    • FLOW

    Cite this