Food and Behaviour Research

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14 December 2016 - The Guardian - Autism linked to vitamin D deficiency during pregnancy, researchers find

Australian Associated Press


Once again, Vitamin D deficiency during pregnancy has been linked to an increased risk for autistic spectrum disorder in the resulting children. For details of this research, see:
Association studies like this one can never provide definitive evidence of cause and effect relationships. That requires randomised controlled human clinical trials (which are rarely possible in pregnancy for practical and/or ethical reasons).

However, only a few weeks ago, the first randomised controlled trial of Vitamin D supplementation in children with autistic symptoms. See:

The important role vitamin D plays in early life is back in the spotlight after Australian researchers noticed a link between a deficiency during pregnancy and autism.

The study found pregnant women with low vitamin D levels at 20 weeks’ gestation were more likely to have a child with autistic traits by the age of six.

The finding has led to calls for the widespread use of vitamin D supplements during pregnancy, just as taking folate has reduced the incidence of spina bifida in the community.

This study provides further evidence that low vitamin D is associated with neurodevelopmental disorders,” said Professor John McGrath from the University of Queensland’s Brain Institute, who led the research alongside Dr Henning Tiemeier from the Erasmus Medical Centre in the Netherlands.

McGrath said supplements might reduce the incidence of autism, a lifelong developmental condition that affects, among other things, how an individual relates to their environment and other people.

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.

Vitamin D usually comes from exposure to the sun, but it can also be found in some foods and supplements.

While it’s widely known vitamin D is vital for maintaining healthy bones, there’s also a solid body of evidence linking it to brain growth.

The study examined approximately 4,200 blood samples from pregnant women and their children, who were closely monitored as part of the long-term “Generation R” study in Rotterdam, the Netherlands.

Blood samples with a vitamin D reading of less than 25.0 nmols is considered deficient.