Taking too much folic acid while pregnant may put daughters at risk of diabetes and obesity

In terms of pregnancy, folic acid is probably the nutrient that has the most emphasis placed on it. It is recommended that women trying to conceive start taking a folic acid supplement and continue with it a few months in to their pregnancy. However, is there a risk with having too much folic acid?

‘Mothers that take excessive amounts of folic acid during pregnancy may predispose their daughters to diabetes and obesity later in life, according to a new study published today in the Journal of Endocrinology. With high dose supplements being widely available, the study calls for a need to establish a safe upper limit of folic acid intake for pregnant women[1].’

A research team gave rats 20 times their recommended dose of folic acid during mating, pregnancy and lactation. The outcome of the experiment had adverse effects on the offspring of the rats who had the excessive dose of folic acid. Those who had the recommended dose of folic acid grew to be healthier.

‘These rats gave birth to babies who grew up to be overweight and insulin resistant in adulthood. The babies also grew up to be deficient in adiponectin – a hormone that protects them against diabetes and obesity – and had irregular feeding behaviour. All of these symptoms were more pronounced in female adults. On the other hand, rats consuming the recommended daily amount of folic acid had babies who grew up to be healthier adults[1].’

Whilst it is still very important for women to take a folic acid supplement and whilst this study was only conducted on rates, it is interesting to consider whether a safe upper limit should be set in place – particularly as many supplements can contain large doses AND many foods are being fortified with folic acid.

“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”, said lead author of the study Professor Elisa Keating. “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[1]”

From this study, we can recognise that there is a need for a safe upper limit of folic acid to be defined. As further studies are conducted, we can determine how to apply research finding to humans.

“Our study clarifies the potential effects of excess folic acid exposure and may play an important role on rethinking current public health policies surrounding folic acid supplementation”.

The researchers will continue to investigate the mechanisms by which folic acid affects the metabolism of rat offspring and how their findings can be applied to human health recommendations[1].’