Have you seen the frightening headlines saying that high folate levels in pregnant mothers are associated with an increased risk of their child having Autism? Once again, there is so much more to the story than meets the eye.
1) This is only a preliminary study and it looked at blood levels of folate, NOT how much folate a woman was taking while pregnant. The evidence associating high levels are folate and Autism is premature and the real story is much more complicated than the study from Johns Hopkins University Bloomberg School of Public Health suggests.
2) High levels of folate in the blood are often related to slow metabolism of folic acid. Slow folic acid metabolism is linked to a number of genetic mutations collectively called MTHFR, which we already know are associated with an increased risk for Autism. The MTHFR mutation is VERY common and may affect up up 40% of Caucasians. MTHFR mutations are also associated with a higher risk of heart disease, depression, anxiety, schizophrenia, ADHD, neurological disorders, migraines, miscarriage, infertility, lymphoma, and leukemia.
3) Women are told to take folic acid in pregnancy to prevent birth defects, but if they have an MTHFR mutation they will be less able to utilize this form of the vitamin. When folic acid is not properly activated and used by the body for normal functions it is more likely to hang around in the blood, showing up as high serum folate. To complicate matters even more, many processed foods (bread, tortillas, crackers, protein bars, energy drinks, etc.) are fortified with folic acid. This was a public health decision that has successfully decreased neural tube defects like spina bifida, but may be detrimental to the many people with MTHFR mutations.
4) Fortunately there are forms of folate (and other B vitamins) that people with MTHFR can properly metabolize. Folate is extremely important for blood cell development, neurotransmitter function, and detoxification pathways.
5) I recommend that all women who are considering pregnancy be tested for MTHFR mutations so that they can start appropriate supplements before they become pregnant.
Just to reiterate, high levels of folic acid in the bloodstream are most likely the result of a genetic mutation associated with autism and are NOT the cause of Autism.
Can nutrition effect fertility? A 
