Grant WB, Soles CM. (2009) Dermatoendocrinol. 1(4): 223-8.
This study examines whether maternal vitamin D deficiency is a risk factor for infantile autism disease (IAD).
We used epidemiologic data seasonal variation of birth rates and prevalence of IAD for cohorts born before 1985.
For seven studies reporting spring-to-summer excess birth rates for IAD, the season progressed from broad near 30 degrees N latitude, spring/summer in midlatitudes, to winter at the highest latitude. Also, using data from 10 studies, we found a strong effective latitudinal (related to wintertime solar ultraviolet B radiation) increase in IAD prevalence.
These findings are consistent with maternal vitamin D deficiency's being a risk factor for IAD, possibly by affecting fetal brain development as well as possibly by affecting maternal immune system status during pregnancy. Further investigation of this hypothesis is warranted.