Yes, too much folic acid during pregnancy really is connected to autism in the offspring

If you've been following this blog for a few years, you know that I've been concerned that folic acid was in part responsible for the rise in autism. I backed off from expressing that worry because of studies showing that folic acid supplementation decreased autism. But it looks like my initial concern was valid.

Johns Hopkins today announced that women with high levels of folic acid and B12 just after giving birth had a much higher chance of having children with autism. Here's an excerpt of the Science Daily article about it:

The researchers found that if a new mother has a very high level of folate right after giving birth -- more than four times what is considered adequate -- the risk that her child will develop an autism spectrum disorder doubles. Very high vitamin B12 levels in new moms are also potentially harmful, tripling the risk that her offspring will develop an autism spectrum disorder. If both levels are extremely high, the risk that a child develops the disorder increases 17.6 times. Folate, a B vitamin, is found naturally in fruits and vegetables, while the synthetic version, folic acid, is used to fortify cereals and breads in the United States and in vitamin supplements.
The findings will be presented May 13 at the 2016 International Meeting for Autism Research in Baltimore.
"Adequate supplementation is protective: That's still the story with folic acid," says one of the study's senior authors M. Daniele Fallin, PhD, director of the Bloomberg School's Wendy Klag Center for Autism and Developmental Disabilities. "We have long known that a folate deficiency in pregnant mothers is detrimental to her child's development. But what this tells us is that excessive amounts may also cause harm. We must aim for optimal levels of this important nutrient."

Because of the research I've done during the past few months, we already limit folic acid in our family diet. I gave away the "enriched pasta" in my food supply, and we only buy cereals without added folic acid. I also tossed the regular multivitamins into the garbage. We eat green salad nearly every day and frequently consume oranges and orange juice, so we get lots of folate in our food. I also take methylfolate and plant-derived folate supplements sometimes because I hope to try to become pregnant again in a few months.