For children whose mothers had low supplemental iron and other risk factors, researchers at the University of California, Davis found a five-fold greater risk of autism.

In a new study from the UC Davis MIND Institute, researchers examined the relationship between maternal iron intake and having a child with autism-spectrum disorder.

The five-fold greater risk of autism was associated with low iron intake— by way of supplements— if the mother was age 35 or older at the time of the child’s birth, or if she suffered from metabolic conditions such as obesity, hypertension or diabetes.

“The association between lower maternal iron intake and increased ASD risk was strongest during breastfeeding, after adjustment for folic acid intake,” Rebecca J. Schmidt, assistant professor in the department of public health sciences and a researcher affiliated with the MIND Institute, said in a news release.

Researchers studied mother-child pairs— including mothers of children with autism and mothers of children with typical development— enrolled in the Northern California-based Childhood Autism Risks from Genetics and the Environment (CHARGE) Study.

They examined maternal iron intake, including vitamins, other nutritional supplements and cereals during the three months prior to and through the end of pregnancy and breastfeeding.

“Iron deficiency, and its resultant anemia, is the most common nutrient deficiency, especially during pregnancy, affecting 40 to 50 percent of women and their infants,” Schmidt said. “Iron is crucial to early brain development, contributing to neurotransmitter production, myelination and immune function. All three of these pathways have been associated with autism.”

Researchers noted the study needs to be replicated and that they’re being cautious with the results.

“In the meantime the takeaway message for women is do what your doctor recommends,” Schmidt said. “Take vitamins throughout pregnancy, and take the recommended daily dosage. If there are side effects, talk to your doctor about how to address them.”