The purpose of this research study is to screen for metabolic abnormalities that are maternal risk factors for having a child with autism.

The study will involve recruitment of 30 mothers of young children with ASD (ages 3-5 years) and 30 mothers of non-ASD children of similar age, respectively labelled ASD-moms and non-ASD-moms. In Phase 1, the levels of certain folate-related and oxidative stress biomarkers (folate, vitamin B12, vitamin E, homocysteine, methylmalonic acid, urinary isoprostanes) and MTHFR mutation analysis will be measured in all the mothers. The investigators expect that approximately 40-50% of the ASD-mothers and approximately 5-10% of the non-ASD-mothers will have abnormal homocysteine levels. In Phase 2, for those mothers with abnormal homocysteine levels, the investigators will treat them with a standard prenatal supplement for 4 weeks, and re-measure their biomarkers. The investigators expect 75-100% of the non-ASD mothers to respond, but only 25-50% of the ASD-mothers to respond. In Phase 3, for those mothers who did not respond to the standard prenatal supplement, the investigators will treat them with an optimized prenatal supplement for 4 weeks and remeasure their biomarkers. The investigators expect that 75-100% of the mothers of both groups will respond to this improved prenatal supplement.

Mothers of children with autism (age 3-5) or typically-developing children (age 3-5) who are not currently taking prenatal vitamins/multivitamins.