Folic acid fortification has significantly reduced neural tube defects (NTDs) in the U.S., but the rise of low-carbohydrate diets raises concerns about adequate folic acid intake among women avoiding fortified foods.
Using data from the National Birth Defects Prevention Study (1998–2011), researchers analyzed 1,740 mothers of infants with NTDs (cases) and 9,545 mothers of infants without birth defects (controls). Carbohydrate intake was assessed via food frequency questionnaires, with restricted intake defined as ≤5th percentile among controls. Logistic regression adjusted for various factors, including maternal demographics and folic acid supplement use.
Key Points:
- Women with restricted carbohydrate intake consumed less than half the dietary folic acid compared to others (p < .01).
- Restricted carbohydrate intake was associated with a 30% higher likelihood of having an infant with anencephaly or spina bifida (AOR = 1.30, 95% CI: 1.02–1.67).
This is the first study linking low-carbohydrate diets to increased NTD risk in post-fortification pregnancies. While the findings highlight potential risks, further research is needed to explore the pathways linking carbohydrate restriction to NTDs and to ensure dietary guidelines adequately address these risks.
