Black Youths May Benefit From Higher Vitamin D Dose
2000 IU/day results in quicker repletion, decreases in arterial stiffness compared with lower dose
FRIDAY, July 30 (HealthDay News) -- Black youths on 2000 IU/day of vitamin D achieve higher vitamin D levels more quickly and have significantly less arterial stiffness than those on 400 IU/day, according to research published online July 21 in the Journal of Clinical Endocrinology and Metabolism.
Yanbin Dong, M.D., of the Medical College of Georgia in Augusta, and colleagues conducted a randomized, blinded, and controlled clinical trial of vitamin D supplementation to determine its effect on 25-hydroxyvitamin D (25[OH]D) level and its relationship to body fat mass and arterial stiffness in black youths. The 49 participants were assigned to either a control group (400 IU/day) or the experimental group (2,000 IU/day).
The researchers found that both groups had increases in serum levels over time, but the experimental group had significantly higher 25(OH)D levels than the control group at eight and 16 weeks. The youths with greater fat mass had somewhat lower vitamin D levels after supplementation than the leaner individuals. Carotid-femoral arterial stiffness, measured by pulse wave velocity, was significantly improved in the experimental group compared to the control group, which showed a small increase.
"In conclusion, the present study indicates that the current adequate intake of vitamin D should be revised upward in black youth. Of importance, atherosclerosis begins in youth, and therefore primary prevention of atherosclerosis should begin in adolescence. More clinical trials are needed to help understand the role of vitamin D deficiency implicated in the pathogenesis of arterial stiffness as a nontraditional risk factor, and to provide interventional evidence for the necessity of maintaining vitamin D sufficiency as early as adolescence," the authors write.