According to an article by Dr. John Cannell, there may be a link to vitamin D deficiency and autism. The article, published in Medical Hypotheses (e-published Oct. 4, 2007) points out that vitamin D deficiency during pregnancy in animals adversely affects many proteins involved in brain development of the fetus. Vitamin D deficient rats, according to Dr. Cannell, are born with “increased brain size and enlarged ventricles, abnormalities similar to those found in autistic children.” Dr. Cannell also points out that children with rickets have several autistic markers that improve with high dose vitamin D supplementation.