Risk Of Too Much Folic Acid While Pregnant

In Medical & Diagnostic

Actively promoted as an important pregnancy supplement, folic acid has been shown to help prevent neural tube defects such as spina bifida and anencephaly, particularly during the first 10 weeks of pregnancy.

Now a new study published in the Journal of Endocrinology has found mothers taking high levels of folic acid during pregnancy may inadvertently be predisposing their daughters to obesity and diabetes. The study calls for the creation of a new safe upper limit for folic acid amongst pregnant women.

Members of a Portuguese research team from the Faculty of Medicine of the University of Porto and the Catholic University of Portugal fed laboratory rats 20 times their recommended daily amount of folic acid throughout mating, the pregnancy period and lactation.

Babies from these litters grew up to be overweight and insulin resistant in adulthood. The babies were also proven to have low levels of adiponectin, a natural hormone that provides protection against diabetes and obesity. In addition, the babies displayed irregular feeding behaviours.

Across the litters of rats that formed the study, female adults showed more pronounced symptoms than male peers. In comparison, rats fed the recommended daily dose of folic acid gave birth to babies who grew up to be healthy adults.

Folic acid is essential to reduce the risk of babies suffering from neural tube defects such as spina bifida, particularly during the first 10 weeks of pregnancy.

The World Health Organisation recommends healthy pregnant women take 0.4 mg of folic acid per day. Women with a family history of neural tube defects are recommended to take ten times this amount through now widely available 5 mg pills.

To date, few studies have explored what the parameters of a safe upper limit of folic acid intake would look like, even though pregnant women globally are consuming increasingly high amounts of folic acid thanks to food fortification policies and widely available multivitamin supplements.

As lead author, Professor Elisa Keating observed, “While taking a minimum of 0.4mg of folic acid per day is essential when pregnant, our study shows that it is possible to have too much of a good thing.” Keating added, “Considering the increasing amount of folic acid consumed during pregnancy through fortified foods, multivitamin pills, and supplements, the search for a safe upper dose of folic acid is urgently needed.”

The research team will continue exploring how folic acid affects the metabolism of rat offspring to identify the activation mechanisms while refining the application of their study findings to a human health context.