The study, which was published Nov. 29 in the journal Molecular Psychiatry, looked at approximately 4,200 blood samples from pregnant women and their children who participated in the long-term “Generation R” study in Rotterdam, the Netherlands. Blood samples with a vitamin D reading of under 25.0 nmols were considered deficient.

The researchers found that pregnant women who were vitamin D deficient at 20 weeks gestation were more likely to have a child with autistic traits by the age of six.

“This study provides further evidence that low vitamin D is associated with neurodevelopmental disorders,” said lead researcher Professor John McGrath of the University of Queensland, Australia. “Just as taking folate in pregnancy has reduced the incidence of spina bifida, the result of this study suggests that prenatal vitamin D supplements may reduce the incidence of autism.”

Autism is a general term for a group of complex disorders of brain development characterized by problems with social interaction, verbal and nonverbal communication, and repetitive behaviors. With the May 2013 publication of the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) all autism disorders have been merged into one umbrella diagnosis of autism spectrum disorder (ASD).

Vitamin D usually comes in the form of sun exposure; however, McGrath feels that pregnant women should boost their levels through supplementation rather than getting more time in the sun.

“We would not recommend more sun exposure, because of the increased risk of skin cancer in countries like Australia,” he said. “Instead, it’s feasible that a safe, inexpensive, and publicly accessible vitamin D supplement in at-risk groups may reduce the prevalence of this risk factor.”

Previous studies have found that vitamin D plays a critical role in fetal brain development, and deficiency during pregnancy has been associated with other conditions including schizophrenia, asthma and reduced bone density. However, it’s important to keep in mind that this study only identified a potential link between vitamin D deficiency and autism, and the “autism-related traits” were self-reported by parents rather than being officially diagnosed by a physician.

Source: The Guardian

Posted by Ray Simon

Ray Simon is a veteran copywriter with more than a decade's worth of experience in the field. He studied journalism at Vanderbilt University, graduating Cum Laude in 2007. Ray currently specializes in writing content and news articles for independent publications.


  1. I agree sun exposure is still beneficial to our health however with crazy weather conditions, it makes you want to avoid sun exposure. I just found out that I’m pregnant, thanks to conceiveeasy. But I will have to check with my obgyn how much vit D I can take.

  2. Great article! Autism is a sun-deficiency/vitamin D-deficiency disease, a point Dr. John Cannell has been making for years. Here are a few of the reasons that he believes that lack of sun exposure and vitamin D are leading to this horror.
    •Both autism and vitamin D deficiency are associated with abnormally high inflammation.
    •Dark-skinned people are far more likely to be vitamin D deficient because they require more sun exposure to produce it. If the theory is correct, the rate of autism among black children would be higher than that among white children due to maternal insufficiency and/or infant insufficiency that would influence brain development. This is exactly the case; children of mothers who have emigrated from Uganda to Sweden, for example, have an autism rate of 15%, which is 200 times that of the general population.
    • There is a close correlation between latitude and autism among countries; the higher the latitude, the higher the rate of autism. High-latitude countries have higher rates of vitamin D deficiency due to a shorter season in which UVB is available to stimulate its production in the skin (see chapter 2). The same relationship of latitude to autism exists within the states of the USA, with northern states having higher rates of autism.
    • In winter, when sun exposure is low, birth rates of autistic children peak.
    • Rickets and autism show similar urban/rural distribution rates.
    • Rickets is an accepted vitamin D-deficiency disease, and urban children have significantly higher rates of both diseases.
    • Pregnant rural women and their children tend to be outside in the sunshine more their urban counterparts, and in urban settings, more air pollution blocks out UVB light.
    • Poor air quality is directly correlated with autism and with profoundly lower serum levels of vitamin D. For example, the Amish of Pennsylvania—mostly rural farmers—have extremely low rates of autism. According to Dr. Heng Wang, who treats Amish people in rural Ohio, their rate of autism is 1 in 1,500, compared to 1 in 166 nationally.
    • Finally, where precipitation rates are high, rates of autism are also high, suggesting a link with sun deprivation.
    For the scientific references and articles for the above statements, visit

Comments are closed.