Several studies show the importance of vitamin D in adolescents and children.
Children worldwide are low in vitamin D and in a safety study, researchers wanted to test doses higher than the 200 IU per day that governments generally recommend. To test short-term safety, investigators recruited 25 apparently healthy school kids, aged 10 to 17, to take 14,000 IU of vitamin D3 per week or a placebo for eight weeks. To test long-term safety, researchers gave 340 more of these adolescents 1,400 IU of vitamin D3 per week, 14,000 IU of vitamin D3 per week or a placebo for one year.
Doctors regularly measured blood levels of calcium and vitamin D before, during and after both studies. Calcium levels did not change in any group. Vitamin D levels remained low in the placebo and 1,400 IU groups, but in the 14,000 IU groups, in both the short- and long-term studies, vitamin D levels rose to healthy levels. Study authors concluded that, “Our research reveals that vitamin D, at doses equivalent to 2,000 IU per day, is not only safe for adolescents, but it is actually necessary for achieving desirable vitamin D levels.”
In a diabetes review, researchers identified five studies that followed about 6,400 infants, 1,400 of whom eventually developed type 1 diabetes and 5,000 that did not. Children who took a vitamin D -supplement were 30 percent less likely to develop diabetes compared to kids who did not take vitamin D. As the dose of vitamin D increased, the likelihood of diabetes decreased.
In an inflammatory bowel disease (IBD) study, researchers from Children’s Hospital in Boston, Massachusetts, measured blood levels of vitamin D in 130 children with IBD, aged 8 to 22. Overall, about 35 percent were deficient in vitamin D. On average, vitamin D levels were 33 percent lower during winter months, and those with darker skin had vitamin D levels 53 percent lower than the group. Those who were taking a vitamin D supplement had 32 percent higher vitamin D levels. Those with higher vitamin D levels had healthier weight, body mass index and digestion, shorter illnesses and less inflammation.
Reference: Journal of Clinical Endocrinology & Metabolism; April 29, 2008, electronic pre-publication.