Researchers found one childhood behavior linked to folic acid use before pregnancy

By Dr. Liji Thomas, MDReviewed by Lauren HardakerSep 1 2026

Researchers followed children through a critical period of early development to investigate whether a simple maternal health behavior before pregnancy was linked to how they later navigated social and behavioral challenges.

Association between preconception folic acid intake and behavioural problems in children aged 2–8 years: a prospective cohort study. Image Credit: Taras Grebinets / Shutterstock

A prospective study published in the European Journal of Nutrition found that maternal preconception folic acid supplementation was associated with a lower risk of problematic peer relationships in offspring, but no association was reported for the other major behavioral difficulties assessed. The fully adjusted analysis found a 34% lower relative risk of peer relationship problems.

Background

Childhood behavioral problems affect approximately 10% to 20% of children worldwide. In Australia, where this study was conducted, these affect about 10% to 13% of children aged 5-12 years, with rates of 39% reported among younger children, particularly by age 3.

Such issues impact later academic and psychosocial function and are associated with mental health disorders later in life.

Prenatal nutrition plays a vital role in neurocognitive development. Folic acid is central to DNA methylation, which occurs during multiple physiological processes in the fetus, including nervous system development. Folic acid is the synthetic form of folate, while folate is naturally obtained from green leafy vegetables, fruits, legumes, liver, and eggs.

However, obtaining adequate folate from diet alone can be difficult during pregnancy. Moreover, major organogenesis is largely complete by the end of the first trimester, making adequate folate status before pregnancy particularly important. For this reason, national and international guidelines recommend 400 mcg of folic acid per day, beginning three or more months prior to conception and continuing through early pregnancy.

The well-established benefit of periconceptional folic acid is the prevention of neural tube defects, as it promotes neural tube closure, an important step in central nervous system development. More recent evidence suggests that folic acid is linked to better cognitive performance in children, and that folic acid in later pregnancy is linked to a lower risk of autism spectrum disorder and attention-deficit hyperactivity disorder in children.

However, findings on these neurodevelopmental and behavioral outcomes remain mixed and inconclusive, perhaps due to inconsistent methodologies. Most studies have also focused on folic acid intake during pregnancy, with relatively little attention to preconception intake, even though folate status before pregnancy may be particularly important.

In this study, the authors aimed to assess associations between preconception folic acid intake and behavioral difficulties in offspring aged 2 to 8 years, a period of rapid cognitive and behavioral development.

Study characteristics

The researchers analyzed data from the Mothers' and their Children's Healthcare Experience Study, a sub-study of the Australian Longitudinal Study on Women's Health. The analysis included 646 children born to 563 mothers from the 1989–95 cohort of the larger study.

The women were aged between 18 and 23 years at baseline, and 28-35 years during the seventh survey.

Mothers reported whether they had taken folic acid as a health behavior in preparation for pregnancy, with responses recorded as yes or no. The researchers then assessed behavioral outcomes in their children using the Strengths and Difficulties Questionnaire (SDQ), a parent-reported measure covering five domains of children's behavioral functioning. The study did not measure folic acid dose, duration of supplementation, or blood folate concentrations.

These included emotional symptoms, peer relationship problems, conduct problems, hyperactivity/inattention problems, and prosocial behavior. The first four were combined into a Total Difficulties Score (TDS), with higher scores indicating greater difficulties. The Prosocial Behavior Score (PS) indicated greater difficulties with lower scores.

Association of folic acid with behavioral problems

Nearly two-thirds of mothers, or 63%, reported taking folic acid supplements before the conception of the child included in the study. Folic acid intake was associated with living in major cities, with higher educational status, and never being married. It was also associated with cessation of drinking in relation to becoming pregnant, intentional pregnancy, and having discussed the importance of folic acid intake with a general practitioner prior to the child's birth.

Overall, 64% of children had at least one SDQ score classified as borderline or abnormal across the behavioral difficulties subscales. Emotional symptoms were more common among girls, especially at age 3. Hyperactivity symptoms were more common among children whose mothers had lower educational attainment or greater difficulty managing their income. Total behavioral problems were more common among children whose mothers reported higher psychological distress or were overweight or obese before conception.

Mothers who did not take folic acid before conception were more likely to have children with peer relationship problems. Compared to this group, the risk of peer relationship problems was 34% lower among children of mothers who did.

The association was more evident among boys and among children aged 2-3 years. No association was observed among children aged 4-8 years or among girls in these subgroup analyses.

It was also stronger after adjusting for maternal vegetable and alcohol consumption. Vegetables are an important dietary source of folate and have been previously linked to behavioral outcomes in children. Moreover, mothers who took folic acid were also more likely to stop drinking and to eat enough vegetables, both of which have been independently associated with favorable behavioral outcomes in the offspring.

“These findings suggest that preconception FA supplementation occurs within a broader pattern of healthier preconception behavior changes, which may also contribute to improved behavioral outcomes in offspring.”

The measured association was therefore not weakened by adjustment for vegetable intake and alcohol consumption, although the authors noted that folic acid use formed part of a broader pattern of healthier preconception behaviors.

No association was observed between preconceptional folic acid intake and total behavioral difficulties, or emotional, conduct, hyperactivity/inattention, or prosocial problems.

Comparison with previous studies

These findings are not fully consistent with earlier studies. Previous research has produced mixed results, including reports of lower risks of total behavioral problems, no overall associations, and higher risks of some specific behavioral problems. One previous study reported a higher risk of peer problems when the mothers had low folate levels in early pregnancy.

The discrepancy in findings could be due to differential effects of folic acid supplementation across exposure timing and dosage, as well as methodological differences. Most studies focused on folic acid intake during pregnancy, whereas the current study examined preconceptional folic acid supplementation. This exposure window may have different implications for fetal neurodevelopment.

The authors postulate that folic acid supports optimal neurodevelopment through its roles in multiple enzymatic reactions involved in neurogenesis and neuronal differentiation, as well as in DNA methylation, which is key to neurogenesis. Alternatively, folic acid might reduce prenatal oxidative stress, mainly by lowering blood homocysteine levels and increasing glutathione concentrations, a key antioxidant that neutralizes reactive oxygen species.

Limitations

The study relied on maternal reports rather than clinical assessments to determine SDQ scores, which may have introduced reporting bias and measurement error. It also relied on self-reported folic acid supplementation, without objective confirmation, which could introduce recall and information bias.

Maternal dietary patterns could have confounded the associations between folic acid intake, as a single nutrient, and behavioral outcomes. The relatively modest sample size may also have limited statistical power, and larger studies may be required to confirm these associations and to identify the mechanisms involved.

Conclusion

The study adds to current knowledge about potential associations between preconceptional folic acid intake and behavioral outcomes during childhood. Maternal folic acid supplementation before conception was associated with a 34% lower risk of peer relationship problems among children aged 2–8 years.

No associations were found with total behavioral difficulties or emotional, conduct, or hyperactivity problems, while the association with prosocial problems was also not statistically significant. As an observational study based on self-reported supplementation and behavioral outcomes, however, it cannot establish that folic acid supplementation caused the lower risk of peer problems.

The authors noted that larger prospective studies are needed to confirm the observed association. Further research could help determine whether the relationship with peer problems is consistently observed across other populations and studies.

The authors said the findings highlight the potential importance of discussing folic acid supplementation prior to pregnancy, during primary care visits, or through public health campaigns.