There is an interesting article about Vitamin D and Autism from a quite reliable medical website which discusses research showing that the rates of Autism appears to be higher in areas where it is more difficult to get enough exposure to sunlight to manufacture Vitamin D.
Note that it appears to be related to the Vitamin D levels of the mothers during pregnancy.
Children and adolescents living in the United States in states with higher levels of ultraviolet B (UVB) exposure are much less likely to develop autism than their counterparts living in states with lower levels of solar UVB exposure, new research shows.
William Grant, PhD, Sunlight, Nutrition, and Health Research Center, San Francisco, California, and John Cannell, MD, Vitamin D Council, San Luis Obispo, California, found that children and adolescents living in states with higher solar UVB doses in summer or autumn had half the rate of autism as their counterparts living in states with the lowest UBV doses.
Rates of autism were also 40% higher in African Americans living in states with the least solar UVB doses compared with white Americans.
Further, African Americans had approximately 40% lower levels of vitamin D than white Americans.
"Summer is when people make the most vitamin D from UVB, and we found that the more UVB dose in summer or fall, the lower the prevalence of autism," Dr. Grant told Medscape Medical News
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As the authors point out, the literature supports the idea that vitamin D deficiency before or during pregnancy is an important risk factor for autism.
For example, as previously reported by Medscape Medical News, the older the man at the time of conception, the higher the risk for autism, a risk that is felt to be due to sporadic DNA mutations.
"Vitamin D can correct for sporadic mutations," Dr. Grant noted, "so it weeds out the bad genes and encourages the good ones."
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However, assuming that solar UVB production of vitamin D is an important factor in reducing autism risk, Dr. Grant advises that pregnant women take enough vitamin D3 to raise serum 25-hydroxyvitamin D concentrations to 30 to 40 ng/mL.
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Dr. Stubbs also noted that there has been at least 1 study in which vitamin D deficiency during pregnancy was associated with an increased risk for clinically significant language difficulties ( Pediatrics 2012;129:485-93).
Animal models of vitamin D deficiency during pregnancy have also shown that low levels have a definite effect on how the brain develops, and the same may be true for humans, although that is speculative, he added.
28 Dec 2012, 4:55 pm
