Dose responses of vitamin D3 supplementation on arterial stiffness in overweight African Americans with vitamin D deficiency: A placebo controlled randomized trial

Study answer

What this study found

Vitamin D3 improved arterial stiffness in a dose-dependent manner, with the largest benefit seen at 4,000 IU/day. Carotid-femoral PWV changed from 6.71 to 6.01 m/s in the 4,000 IU/day group (change -0.70, 95% CI -1.07 to -0.32), compared with 0.02 (-0.34 to 0.38) in the 600 IU/day group and -0.11 (-0.50 to 0.27) in the 2,000 IU/day group; the group-by-time interaction was P<0.01. Carotid-radial PWV also favored the higher dose, with a group-by-time interaction of P=0.03. Serum 25(OH)D increased with dose, and no significant blood pressure changes or adverse events were reported.

Study & population

Placebo-controlled randomized trial in overweight African American adolescents and young adults with vitamin D deficiency/suboptimal status (25[OH]D <20 ng/mL), aged 13 to 45 years, conducted in Augusta, Georgia.

Intervention

Oral vitamin D3 capsules were given under supervised monthly dosing for 16 weeks at 18,000 IU/month (~600 IU/day), 60,000 IU/month (~2,000 IU/day), or 120,000 IU/month (~4,000 IU/day), with placebo as the comparator.

Key limitation

The trial was small, with only 17 to 18 participants per active dose arm, and lasted only 16 weeks.

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Original abstract