Female? Get Your Folic Acid Supplement

Folic acid is essential in pregnancy to prevent serious birth defects, maternal anemia, and low infant birth weight. In North America, folic acid fortification of white flour, pasta products, and other grain products has been mandatory since 1998. Still, most women of childbearing age are advised to take a folic acid supplement, either in the form of prenatal vitamins (if pregnant) or in a daily multivitamin (if not pregnant). With folic acid being added to the food supply, researchers in Toronto, Canada sought to find out if pregnant women were receiving adequate amounts of folic acid through diet alone (J Nutr 2006;136:2820-2826).

Sixty-two pregnant women were recruited to participate in the study. They were all between 16 and 40 years of age, at or above 36 weeks of gestation, otherwise healthy nonsmokers who planned to breastfeed for at least four months after they delivered. At delivery, the women were randomly placed in one of three supplementation groups: a placebo or one of two types of folic acid supplements.

All women also received a multivitamin, mineral, and iron supplement which did not include folic acid. They were also asked to complete 3-day food records at the beginning of the study (at 36 weeks of gestation) and at 4 and 16 weeks postpartum. Using the food records, the researchers were able to assess how much folic acid the women were receiving through their diet as opposed to any supplementation they were receiving.

They found that 36% of the pregnant subjects were not receiving the recommended daily intake of folic acid through dietary means alone, despite the government-mandated supplementation of the food supply. For those lactating, 32% were below the recommended dietary intake. Without that fortification, the researchers calculated that 98% of the women would not have received enough folic acid in their diet.

What this means for you:

I routinely recommend that women in my practice who are of childbearing age take a multivitamin that contains folic acid - at least 400 mcg in each pill. This study clearly shows just how important such additional supplementation is.

First posted: November 1, 2006