title: A prospective randomized controlled trial of the effects of vitamin D supplementation on cardiovascular disease risk.
abstract: Vitamin D (VitD) supplementation has been advocated for cardiovascular risk reduction; however, supporting data are sparse. The objective of this study was to determine whether VitD supplementation reduces cardiovascular risk. Subjects in this prospective, randomized, double-blind, placebo-controlled trial of post-menopausal women with serum 25-hydroxyvitamin D concentrations >10 and <60 ng/mL were randomized to Vitamin D3 2500 IU or placebo, daily for 4 months. Primary endpoints were changes in brachial artery flow-mediated vasodilation (FMD), carotid-femoral pulse wave velocity (PWV), and aortic augmentation index (AIx). The 114 subjects were mean (standard deviation) 63.9 (3.0) years old with a 25-hydroxyvitamin D level of 31.3 (10.6) ng/mL. Low VitD (<30 ng/mL) was present in 47% and was associated with higher body-mass index, systolic blood pressure, glucose, CRP, and lower FMD (all p<0.05). After 4 months, 25-hydroxyvitamin D levels increased by 15.7 (9.3) ng/mL on vitamin D3 vs. -0.2 (6.1) ng/mL on placebo (p<0.001). There were no significant differences between groups in changes in FMD (0.3 [3.4] vs. 0.3 [2.6] %, p = 0.77), PWV (0.00 [1.06] vs. 0.05 [0.92] m/s, p = 0.65), AIx (2.7 [6.3] vs. 0.9 [5.6] %, p = 0.10), or CRP (0.3 [1.9] vs. 0.3 [4.2] mg/L, p = 0.97). Multivariable models showed no significant interactions between treatment group and low VitD status (<30 ng/mL) for changes in FMD (p = 0.65), PWV (p = 0.93), AIx (p = 0.97), or CRP (p = 0.26). In conclusion, VitD supplementation did not improve endothelial function, arterial stiffness, or inflammation. These observations do not support use of VitD supplementation to reduce cardiovascular disease risk.
authors.affiliation: University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
authors.forename: Adam D
authors.initials: AD
authors.lastname: Gepner
authors.forename: Rekha
authors.initials: R
authors.lastname: Ramamurthy
authors.forename: Diane C
authors.initials: DC
authors.lastname: Krueger
authors.forename: Claudia E
authors.initials: CE
authors.lastname: Korcarz
authors.forename: Neil
authors.initials: N
authors.lastname: Binkley
authors.forename: James H
authors.initials: JH
authors.lastname: Stein
mesh_terms: D000368:Aged; D001786:Blood Glucose; D001794:Blood Pressure; D015992:Body Mass Index; D001916:Brachial Artery / Q000187:drug effects*; D002318:Cardiovascular Diseases / Q000178:diet therapy*; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D006339:Heart Rate; D006801:Humans; D008875:Middle Aged; D017698:Postmenopause; D011446:Prospective Studies; D012307:Risk Factors; D014664:Vasodilation / Q000187:drug effects*; D014807:Vitamin D / Q000008:administration & dosage* / Q000031:analogs & derivatives / Q000097:blood
chemical_list: D001786:Blood Glucose; D014807:Vitamin D; C104450:25-hydroxyvitamin D