May 28, 2008 -- Children and teens need 10 times more than the recommended
dose of vitamin D, a clinical trial suggests.
"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
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."
The researchers strongly suggest that many children are getting far too
little vitamin D, especially those who do not get plenty of sun exposure
throughout the year. The skin makes vitamin D when exposed to direct
El-Hajj Fuleihan and colleagues note that every 100 IU of oral vitamin D3
raises levels by about 1 ng/mL. Thus, children with levels below 20 ng/mL --
the average for untreated children in this study -- would benefit from daily
supplementation with 2,000 IU of vitamin D3.
"The high prevalence of [too-low vitamin D levels] worldwide across all
age groups, the fact that many diseases of adulthood are rooted in the
pediatric age group, and the safety data available to date render it quite
compelling to modify the current recommendations regarding adequate vitamin D
intake not only for adults but also for children," the researchers
This study was supported by grants from Nestle, which makes
vitamin-D-fortified milk products, and from Merck, which makes a vitamin D
supplement popular in Europe.
El-Hajj Fuleihan and colleagues report their findings in the advance online
edition of the July issue of the Journal of Clinical Endocrinology &
Before starting your child on supplements or vitamins, always consult
with your pediatrician.