Autism prevalence in USA

[Don Smith]

Click on the link below and you can download a pdf copy of this "landmark" study regarding autism and vitamin D.


Autism prevalence in the United States with respect to solar UV-B doses: An ecological study

Volume 5, Issue 1 January/February/March 2013
Authors: William B. Grant and John J. Cannell

Abstract:
Evidence is mounting that vitamin D deficiency is intimately involved in autism. We report on autism prevalence by US state for those aged 6–17 y in 2010 with respect to indices of solar UV-B (UVB) doses. We calculated autism prevalence rates for white, black and Asian Americans by using total prevalence and relative populations of minors for each ethnic group by state. Analyses omit AK and HI (considered extreme cases), WY (no data), along with AZ and ND for black Americans (low numbers) and DC, ME, MT, ND and SD for Asian Americans (low numbers).

For white Americans, the regression coefficient for solar UVB doses and autism prevalence ranged from -0.52 in January to -0.57 in October. For black Americans, the regression coefficient for latitude was 0.61, whereas those for solar UVB ranged from -0.55 to -0.61. For Asian Americans, the values for solar UVB ranged from -0.28 to -0.38.

The inverse correlation between solar UVB and autism prevalence is similar to that for many types of cancer in the US. The journal literature indicates that adverse effects on fetal brain development during pregnancy due to vitamin D deficiency can explain these findings. However, we cannot rule out a role of vitamin D deficiency in early life.

These results add to the evidence that vitamin D deficiency may be an important risk factor for autism and suggest that pregnant women and autistic individuals raise their serum 25-hydroxyvitamin D concentrations above 30 ng/ml (75 nmol/L).

http://www.landesbioscience.com/journals/dermatoendocrinology/article/22942/

[Don Smith]

I was curious about the fact that Arizona and Hawaii data was excluded from the study and so I sent an email to my friend Bill Grant asking some questions. He responded by clarifying that only African American data were excluded because of the small numbers.

He also stated (as I expected) that AZ was lower in autism prevalence for all populations. Thus, the premise that adequate UVR/vitamin D levels is "preventative" for autism is supported.

This is important because a recent CDC report stated that "As of 2012, one in 50 kids between the ages of 6 and 17 has some form of autism, compared with one in 88 only five years earlier."