This diary takes its title from that of a Scientific American article published today that cites three studies potentially correlating low early-life vitamin D levels with autism.
The article describes two studies of immigrant Somali mothers in Sweden and Minnesota, and mentions a third study of autism levels in sunnier vs. rainier areas of the Northwest U.S.
Sunlight exposure and nutrition determine Vitamin D levels in humans. Sunlight exposure and nutrition are also, in part, functions of race, weather, wealth, and culture and as discussed in the article.
Since this will get interesting enough, below the fold I'll just supply a few fairly-used paragraphs from the Scientific American article and solicit comments.
Last summer, Swedish researchers published a study in Developmental Medicine and Child Neurology that found the prevalence of autism and related disorders was three to four times higher among Somali immigrants than non-Somalis in Stockholm.
In Minnesota, where there are an estimated 60,000 Somali immigrants, the situation was quite similar: There, health officials noted reports of autism among Somali refugees, who began arriving in 1993, comparable to those found in Sweden.
What seemed to link the two regions was the fact that Somalis were getting less sun than in their native country—and therefore less vitamin D. The vitamin is made by the skin during sun exposure, or ingested in a small number of foods. At northern latitudes in the summertime, light-skinned people produce about 1,000 international units (IUs) of vitamin D per minute, but those with darker skin synthesize it more slowly, says Adit Ginde, an assistant professor at the University of Colorado Denver School of Medicine. Ginde recommends between 1,000 to 2,000 IUs per day, calling current recommendations of 200 IUs per day outmoded.
Because there are compelling arguments that the lighter "races" themselves are evolutionary responses to the effect on pregnancy of low Vitamin D levels in dimmer climates, to me this article makes a lot of sense.
At the same time, adding more hot buttons to the already hot-button issue of autism will probably make for spirited discussion.
So, what do you think?