Table 2.

Double-blind, placebo- and randomized-controlled trials that do not favor supplementation with vitamin D

Ref.	Country	Participants	Intervention	Duration of follow-up	Results
Gepner et al[53]	United States	114 post-menopausal women	Vitamin D3 2500 IU or placebo, daily for 4 mo	4 mo	No significant effects of vitamin D supplementation to reduce cardiovascular disease risk
Jorde et al[54]	Norway	330 overweight or obese subjects	Vitamin D [cholecalciferol, vitamin D(3)] 40000 IU, vitamin D 20000 IU, or placebo per week for 1 yr	1 yr	No significant effect of vitamin D on glucose tolerance, blood pressure or serum lipids
Marckmann et al[55]	Denmark	52 chronic kidney disease patients with vitamin D deficiency	40000 IU of cholecalciferol orally per week for 8-wk	8 wk	No significant impact on functional markers and plasma concentrations of biomarkers related to cardiovascular disease
Muldowney et al[56]	Ireland	394 healthy participants	Cholecalciferol at doses of 0, 5, 10 , or 15 μg/d (0-600 IU) for 22 wk	22 wk	No significant effects of supplementation on CVD risk biomarkers
Scragg et al[57]	United Kingdom	95 elderly adults	A single oral dose of 2.5 mg cholecalciferol or placebo	5 wk	No significant effect of vitamin D supplementation to change blood pressure or serum cholesterol
Stricker et al[58]	Switzerland	62 peripheral arterial disease patients with vitamin D deficiency	A single, oral supplementation of 100000 IU vitamin D3 or placebo	1 mo	Unlikely to influence endothelial function, arterial stiffness, coagulation and inflammation
Thadhani et al[59]	United States	227 patients with chronic kidney disease	Paricalcitol or placebo over 48 wk	48 wk	Unlikely to alter left ventricular mass index or improve certain measures of diastolic dysfunction
Wood et al[60]	United Kingdom	305 healthy postmenopausal women	A daily capsule of 400 or 1000 IU vitamin D(3) or placebo for 12 mo	12 mo	Unlikely to reduce CVD risk factors
Yiu et al[61]	Hong Kong	100 patients with type 2 DM	Oral vitamin D (5000 IU/d) or placebo per day for 12 wk	12 wk	No significant effect on vascular function or serum biomarkers of inflammation and oxidative stress

CVD: Cardiovascular disease; IU: International units; DM: Diabetes mellitus.