It's one of parents' least favorite activities — rearranging work/life schedules because one has to stay home with a sick child. Even just a cold requires some supervision and TLC. Wouldn’t it be great if just feeding your kid some vitamin D could help prevent such occurrences? Unfortunately, a new study just published in JAMA doesn't lend any hope that extra vitamin D can help.
The authors of the report, led by Mary Aglipay from St. Michael’s Hospital in Toronto, Canada, wanted to know if high doses of vitamin D (2000 IU/day) would help children avoid upper respiratory infections compared to a usual supplemental dose of 400 IU/day.
To investigate this question, they randomly assigned 700 young children (on average 3 years old, range 1-5 years) to receive either 2000 or 400 IU vitamin D per day for at least 4 months. The children were then followed to see if there were any differences between the groups with respect to the number of lab-confirmed upper respiratory tract infections. But there was no difference between the groups. In addition, the time to the first lab-confirmed infection did not differ between the groups. These results held, even though the blood levels of the vitamin were higher in the high-dose group.
Thus, it seems that pumping a child full of extra vitamin D isn’t going to have a miraculous effect on the chance they’ll develop an upper respiratory infection — at least not compared to a standard dose of vitamin D. We already know that vitamin D is necessary for normal growth and development, but beyond that, mega-doses won’t protect against the common cold.