USPSTF: Daily folic acid for all women who plan to have children

The results of four recent studies support the long-standing recommendation from the U.S. Preventive Services Task Force that all women “planning or capable” of becoming pregnant should take a daily supplement of folic acid to prevent neural tube defects.

In 1996, the task force first recommended that women supplement their diet with 400 mcg folic acid daily if there was a chance they could become pregnant and 800 mcg folic acid daily if they were planning to become pregnant.

In its update, the task force cited the results of four studies published since 1996 that showed a beneficial effect from folic acid. Specifically, the results of a meta-analysis indicated a decreased OR of 0.67 for neural tube defects with the use of folic acid in case-control studies and an OR of 0.52 for randomized controlled trials and cohort studies. Reductions in neural tube defects such as spina bifida or anencephaly associated with periconceptional folic acid supplementation had ORs that ranged from 0.11 to 0.65.

The new recommendations also allay concerns raised in 2006 about possible harmful effects of contraceptive folic acid. The task force found that there was no evidence of drug interactions, allergic reactions or carcinogenic effects associated with the supplement.

The task force said there was no “clear, consistent” evidence that folic acid leads to an increased rate of twins. – by Jason Harris

USPSTF. Ann Intern Med. 2009;150:626-631.

This report is focused narrowly on the use of supplements in pregnant women and does not reference some recent data suggesting that individuals with vitamin B₁₂ deficiency might be exposed to greater risk of anemia and neurocognitive problems if given folic acid without also being given B₁₂. The paper is also misleading as to the prevalence and risk of B₁₂ deficiency. While it is true that younger women, childbearing age, are in general less likely to have B₁₂ deficiency than older people, this is not the case in certain demographic groups. Hispanic and African American young women have a higher prevalence of B₁₂ deficiency than that of the Caucasian population. Pregnant women who are taking supplemental folic acid and who may be B₁₂ deficient are potentially at risk for possible neurological damage.

– Ralph Green MD, PhD

HemOnc Today Editorial Board member