But the headlines are also somewhat accurate. This highlights a distinction that is extremely important for the future of this research. For decades, we’ve known that folate plays a critical role in formation of the spine of a fetus. When a pregnant person doesn’t take in enough folate, the fetus has a much greater risk of being born with a splayed vertebral column (spina bifida), or a similar abnormality on the spectrum neural tube defects.

These debilitating spinal birth defects became more common (as did other symptoms of folate deficiency), as our diets came to consist of ever more processed foods. While folate is abundant in fruits and vegetables, highly processed foods tend to be stripped of nutrients and so must be “fortified” with synthetic versions of the nutrients. Some countries, including the U.S., passed laws requiring that folate be added to processed foods.

To be doubly safe–females of childbearing age have long been advised to take supplemental folate. (“Prenatal multivitamins” are loaded with folate.)

The effort was extremely effective. Rates of neural tube defects plummeted.

But they didn’t go to zero, and that’s because a lot of people still don’t get enough folate around the time that they conceive, and in the early stages of pregnancy.

So the message from today’s news is potentially dangerous, if it detracts from that momentum.

What is unique today is the finding that blood tests done around the time of birth found that about 10 percent of mothers had excessively high levels of folate and/or vitamin B12 in their blood. Those people had an increased risk of having a child who would later be diagnosed with ASD.

I spoke with one of the researchers, Dani Fallin, who is chair of the department of mental health at Johns Hopkins. She specified that the team did not have access to data that could correlate the use of supplements with the high levels of folate or B12 in people’s blood. “We would want to understand why these women have such high levels of folate in their blood,” she explained, “whether it's about fortification of foods, supplementation, genes and enzymes involved in metabolism, or a combination of those things.”

If anything, these findings would suggest that one day it might be worthwhile to consider screening pregnant women with blood tests to look for toxic levels of folate or B12. Fallin put the findings cautiously, succinctly: “We see this as evidence that there is a subset of people for whom excessively high levels of folate (in their blood) might be at risk for autism (in their children).”

At this point, though, the evidence is extremely premature. The findings have not been peer-reviewed or published in a journal; the press release referred only to a brief scientific abstract that is being presented at a conference this week.