CHEVY CHASE, Md. Vitamin D deficiency is associated with arterial stiffness, a risk factor for heart disease and stroke in African-American teens, according to a new study accepted for publication on The Endocrine Society's website, Endo-society.org.
"While we think of the sun as providing humans with most of our body's requirement of vitamin D, 95% of the 44 black teenagers living in sunny Georgia who took part in this study were classified as vitamin D deficient," stated Yanbin Dong, lead author of the study. "Our study shows that vitamin D supplementation may improve cardiovascular health in black teens who don't get enough vitamin D from their diet and sun exposure."
In this study, 44 black teenagers (male and female) were randomly assigned to receive either 400 IU of vitamin D per day as recommended by the American Academy of Pediatrics or 2,000 IU of vitamin D per day. Study subjects taking 400 IU of vitamin D per day did not achieve vitamin D sufficiency, while their peers who took 2,000 IU of vitamin D per day on average became vitamin D sufficient.
Black teens taking vitamin D supplementation of 2,000 international units (IU) per day had a decrease in central arterial stiffness.
"Our study is the first clinical trial of vitamin D intervention to use 2,000 IU in black subjects and to include cardiovascular risk factors as outcomes in youth," Dong said. "Our study indicates that the current recommendations for vitamin D intake in black teenagers may need to be revised upward."