Prenatal Iron Intake Linked to Autism

A new study indicates that mothers with lower iron intake during pregnancy and breastfeeding may be more likely to have children with autism spectrum disorder (ASD).

The study, carried out by the UC Davis School of Medicine, was the first to investigate the link between iron intake and ASD. Previous studies have found similar links between folic acid intake and ASD.

The research drew a connection between lower iron intake (less than 51 milligrams per day) and higher autism risk, especially during breastfeeding. This correlation was stronger for mothers over the age of 35 and for those with hypertension, diabetes, or obesity.

Iron deficiency is fairly common during pregnancy, typically affecting 40 to 50 percent of women and their infants. But iron is one of the most critical nutrients for a baby’s growth, playing a role in brain development and immune function — two pathways that have been associated with autism.

The researchers pointed out that most of the women in the study were getting more than the currently recommended amount of iron, which is about 27 mg per day for pregnant women. If the results can be replicated and the link between iron intake and ASD becomes more definitive, it may indicate that the current iron recommendations for pregnant women are too low.

The lead researcher on the study, Rebecca Schmidt, says the link between iron intake and autism risk is just a preliminary one, and warrants further research. It's important to talk to your doctor about your iron needs and to take only the recommended amount from supplements, as too much iron from supplements can be toxic. But if you're worried about your iron levels, look toward natural sources — like red meat, beans, and dark chocolate — which carry no toxicity risk.

The U.S. autism rate is on the rise, with 1 in 68 children diagnosed in 2014 (compared to 1 in 150 in 2000). Nearly one third of children with ASD are also thought to have ADHD. While the exact cause of the ASD increase is still unknown, genetic factors and maternal nutrition during pregnancy are hot topics of research. “Most women in America just don’t get quite enough iron from the diet,” Schmidt said.

“I think most women know they’re supposed to take a prenatal vitamin,” she added, “but not all women know why they’re taking it.”