No need for panic: folic acid is still essential to maintain a healthy pregnancy
Women of childbearing age are encouraged to supplement with 400 mcg/day of folic acid to reduce the risk of neural tube defects in their children. The current Dietary Reference Intake for folate during pregnancy is 600 mcg/day, yet women who are considered at high risk for having children with neural tube defects are often advised to consume up to 5000 mcg/day. Recent data suggests that this practice may be harmful – so is it cause for alarm?
Valera-Gran and colleagues conducted a prospective cohort study where they followed 2213 children born in Spain. Mothers were surveyed to determine their dietary folate intake and folic acid supplementation practices. Children were tested for their psychomotor and mental development when they reached 1 year of age. When they compared children born to women supplementing with over 5000 mcg/day to those born to women taking 400-1000 mcg/day, they found that children born to women taking over 5000 mcg/day had a significantly lower psychomotor development score compared to those born to women taking 400-1000 mcg/day.
So is this cause for alarm? Should women stop taking their folic acid supplements? Absolutely not. First off, let’s not forget that there is an extremely large body of evidence to demonstrate that folic acid use during around conception reduces the risk of neural tube defects. This is why the United States and many other countries fortify their food supply with folic acid, and this is why folic acid was named a “Nutrient of Concern” for women of childbearing age by the 2010 Dietary Guidelines Advisory Committee.
Next, we need to recognize that the practice of supplementing with 5000 mcg/day during pregnancy is only recommended for women with high-risk pregnancies (e.g., for women who have previously had a child affected by a neural tube defect), and is not a practice recommended for the general population.
We also should note that this is the first time such a relationship has been documented in the literature – in fact, there are other reports that suggest that maternal folic acid use during pregnancy is actually associated with an increase in psychomotor function of the offspring (see here and here). And last but not least, let’s not forget that this was not an intervention study so a cause-and-effect relationship cannot be established from this study. Correlation does not imply causation.
At the end of the day, what do we know? We know that folic acid use during pregnancy is safe and effective for reducing the risk of neural tube defects. We know that women with high-risk pregnancies should supplement with 5000 mcg/day. And until we see compelling data that says otherwise, the status quo shouldn’t change: women need their folic acid.
Valera-Gran D, et al. Folic acid supplements during pregnancy and child psychomotor development after the first year of life. JAMA Pediatr 2014; 168(11): e142611. doi: 10.1001/jamapedaitrics2014.2611
Julvez J, Fortuny J, Mendez M, et al. Maternal use of folic acid supplements during pregnancy and four-year-old neurodevelopment in a population-based birth cohort. Paediatr Pernatal Epidemiol 2009; 23(3): 199-206.