The current recommended daily allowance (RDA) of vitamin D for children is 200 International Units (IUs), but new research reveals that children may need and can safely take ten-times that amount. According to new research this order-of-magnitude increase could improve the bone health of children worldwide and may have other long-term health benefits.
There are two counterposing factors for me when processing these sorts of medical findings. First, I am cautious about overreacting based on new medical research, because so much of this ends up overturned upon second-look as there are various confounds and variables unaccounted for. Second, I believe there are strong evolutionary hints that Vitamin D deficiency causes some serious reductions in fitness on the physiological/health margins. What I mean is that there is a wealth of data that the genetic variants which are implicated in lighter complexion have been powerfully driven by natural selection within the last 10,000 years in various human populations. It seems to me that the most plausible model to explain this genetic change is an environmental reduction in Vitamin D and this micronutrient’s essential role in sustaining immune health. But most plausible does not mean the correct, so we must weight that prior accordingly. Additionally, most modern humans are not living on the physiological marings, we’re healthy and wealthy, so we can take nutrient hits (if they are hits) without putting our lives at risk. Of course, if you are dark-skinned, that’s another prior you should pump in, because it is almost assured that you have a deficiency if you reside at temperate latitudes.
For the record, I am actually taking 2,000 IU Vitamin D pills every day to keep my levels up. That’s the dosage recommended in this research for adolescents.