The study, which was published in the journal Molecular Psychiatry, discovered that pregnant women who had low vitamin D levels when they were 20 weeks pregnant were more likely to have a child who displayed autistic traits by the age of 6. For the study, researchers analyzed approximately 4,200 blood samples from pregnant women and their children in the Netherlands.
Vitamin D is essential for healthy bones, and people often get it from being exposed to the sun. However, it’s also possible to get doses of the vitamin from some foods and vitamin supplements.
Autism and autism spectrum disorder (ASD) are terms for a group of disorders of brain development, according to the autism awareness organization Autism Speaks. The disorders are characterized by “difficulties in social interaction, verbal and nonverbal communication, and repetitive behaviors.” ASD may be linked to “intellectual disability, difficulties in motor coordination and attention, and physical health issues such as sleep and gastrointestinal issues,” the organization says.
According to the Centers for Disease Control and Prevention, about one in 68 children has the disorder, and it’s 4.5 times more common in boys than girls.
Unfortunately, vitamin D deficiency is fairly common in pregnant women, women’s health expert Jennifer Wider, tells Yahoo Beauty. According to data from the American Pregnancy Association, between 40 and 60 percent of the entire U.S. population is vitamin D deficient, and those numbers include pregnant women.
While prenatal vitamins include vitamin D, Wider notes that average versions contain about 400 IU of the vitamin, which may not be enough. “After this study and others like it, doctors will likely recommend supplementation,” she says.
Other research has shown that vitamin D plays a role in the development of the brain and nervous system, Wider notes, adding that it “makes sense” that low vitamin D may be linked with neurodevelopmental disorders such as autism. (In fact, previous research by John McGrath, MD, PhD, who led this study, found a link between low vitamin D levels in newborns and an increased risk of schizophrenia.)
Some foods, such as eggs, salmon, and sardines, contain vitamin D, New York-based dietitian and nutritionist Jessica Cording, tells Yahoo Beauty. “Mushrooms are one of the few plant sources, but they don’t provide a lot,” she adds. Most vitamin D is consumed through vitamin D-fortified foods, such as milk.
Wider expects that more doctors will start recommending vitamin D supplements to pregnant women as a result of these findings. However, if you’re pregnant and concerned about how your vitamin D level may impact your baby, talk to your doctor.