A long article in the Scientific American examines the evidence.

Preliminary studies in Sweden and Minnesota suggest that vitamin D, the 'sunshine' vitamin, might possibly play a role in the development of autism.

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. Within several years of arrival, dozens of the Somali families whose children were born in the U.S. found themselves grappling with autism. The number of Somali children in the city's autism programs jumped from zero in 1999 to 43 in 2007; the number of Somali-speaking children in the Minneapolis school district increased from 1,773 to 2,029 during the same period.

Few, if any, Somalis had ever seen anything like it. Such a disease was unknown in Somalia and there is no word int he language to describe it.

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.

Read the full article.

First published in 2009

Click here for more articles on the causes of autism

Back to top