"Our research reveals that vitamin D, at doses equivalent to 2,000 IU a day, is not only safe for adolescents, but it is actually necessary for achieving desirable vitamin D levels," study leader Ghada El-Hajj Fuleihan, MD, of the American University of Beirut Medical Center in Lebanon, says in a news release.
Kids are advised to get a daily vitamin D dose of 200 IU. That suggestion came from an Institute of Medicine panel that based its recommendation on the amount of vitamin D needed to prevent rickets in infants.
However, more and more vitamin D experts have begun to suggest that children and adults need much more vitamin D than previously recognized.
New evidence strongly supports this opinion. El-Hajj Fuleihan and colleagues enrolled 340 schoolchildren in a one-year study. These 10- to 17-year-old kids attended schools in Beirut, Lebanon.
A third of the kids received an inactive, sham treatment. Another third got the recommended 200 IU/day dose of vitamin D3 (as a weekly dose of 1,400 IU). And, after an earlier safety study showed it would not be toxic, the remaining third of the kids got 2,000 IU/day of vitamin D3 (as a weekly dose of 14,000 IU) -- 10 times the recommended dose for adequate daily intake.
After a year of treatment, vitamin D levels went up slightly in the placebo group, and went up slightly more in the normal-dose vitamin D group -- to 16 ng/mL for girls and to 20 ng/mL for boys. That's well below the 30 ng/mL level the U.S. National Institutes of Health states may be desirable for overall health and disease prevention.
But kids who got 2,000 IU/day vitamin D3 saw their vitamin D levels soar -- to 38 ng/mL for girls and to 35 ng/mL for boys. None of the kids showed signs of vitamin D toxicity.
"Supplementation of children and adolescents with 2,000 IU a day of vitamin D3 is well tolerated and safe," El-Hajj Fuleihan says. "This is particularly relevant in light of the increasingly recognized health benefits of vitamin D for adults and children."