High-dose vitamin D may optimize vitamin D status, counteract aortic stiffness progression in black youth

Dong Y. J Clin Endocrinol Metab. 2010;doi:10.1210/jc.2010-0606.

Black youth may benefit from a revised vitamin D intake level of 2,000 IU compared with the currently recommended adequate intake of 400 IU, new data suggested.

Compared with black adolescents assigned to 400 IU of vitamin D per day who did not achieve vitamin D sufficiency at 16 weeks, those assigned 2,000 IU per day were vitamin D sufficient by study end.

“Our study shows that vitamin D supplementation may improve cardiovascular health in black teens who do not get enough vitamin D from their diet and sun exposure,” Yanbin Dong, MD, PhD, of the Medical College of Georgia, said in a press release.

The Vitamin D Supplement Study for Adolescents compared an experimental high-dose of 2,000 IU vitamin D with 400 IU per day, as currently recommended by the American Academy of Pediatrics. The study included 25 normotensive black adolescents in the experimental arm and 24 adolescents in the control arm (mean age, 16.3 years). The researchers used DXA to evaluate the association between 25 hydroxyvitamin D concentrations and total BMI and used pulse wave velocity to determine central arterial stiffness.

Black adolescents assigned to the 2,000 IU dose experienced significant improvements in carotid-femoral pulse wave velocity at 16 weeks (5.33 vs. 5.41 at baseline; P=.031). Conversely, adolescents assigned 400 IU showed worsened central arterial stiffness during 16 weeks; carotid-femoral pulse wave velocity increased from 5.38 at baseline to 5.71 by study end (P=.016).

The experimental group achieved significantly higher 25 hydroxyvitamin D concentrations at weeks 8 (70.9 nmol/L vs. 51.2 nmol/L) and 16 (85.7 nmol/L vs. 59.8 nmol/L) compared with the control group.

According to the researchers, additional clinical trials are needed to further understand vitamin D deficiency’s role in the pathogenesis of arterial stiffness in adolescents.