Folic acid: A recommendation worth making

The US Preventive Services Task Force (USPSTF) recently published a draft recommendation on the use of folic acid before and during pregnancy to prevent fetal neural tube defects.¹ This reaffirmation of the 2017 recommendation states that all persons planning to or who could become pregnant should take a daily supplement of folic acid.^1,2 This is an “A” recommendation.

Neural tube defects are caused by a failure of the embryonic neural tube to close completely, which should occur in the first 28 days following fertilization. This is why folic acid is most effective if started at least 1 month before conception and continued for the first 2 to 3 months of pregnancy.

An estimated 3000 neural tube defects occur each year in the United States. Spina bifida, anencephaly, and encephalocele occur at respective rates of 3.9, 2.5, and 1.0 in 10,000 live births in the United States, which totals 7.4/10,000.³

Folic acid, if taken before and during pregnancy, can prevent about half of neural tube defects; if taken only during pregnancy, it prevents about one-third. If 50% of neural tube defects could be prevented with folic acid supplements, the number needed to treat (NNT) to prevent 1 case is about 3000.⁴

The case for supplementation. The recommended daily dose of folic acid is between 0.4 mg (400 μg) and 0.8 mg (800 μg), which is contained in many multivitamin products. Certain enriched cereal grain products in the United States have been fortified with folic acid for more than 2 decades, but it is unknown whether women in the United States are ingesting enough of these fortified foods to provide maximum prevention of neural tube defects. There are no known harms to mother or fetus from folic acid supplementation at recommended levels.

Room for improvement. Only 20% to 40% of people who are pregnant or trying to get pregnant, and 5% to 10% of people with an unplanned pregnancy, take folic acid supplements. Half of all pregnancies in the United States are unplanned.⁴ This leaves a lot of room for improvement in the prevention of neural tube defects.

An important recommendation, even if you don’t see the results. The NNT to prevent a case of neural tube defect is high; most family physicians providing perinatal care will not prevent a case during their career. And, as with most preventive interventions, we do not see the cases prevented. However, on a population-wide basis, if all women took folic acid as recommended, the number of severe birth defects prevented would be significant—making this simple recommendation worth mentioning to those of reproductive age.

The US Preventive Services Task Force (USPSTF) recently published a draft recommendation on the use of folic acid before and during pregnancy to prevent fetal neural tube defects.¹ This reaffirmation of the 2017 recommendation states that all persons planning to or who could become pregnant should take a daily supplement of folic acid.^1,2 This is an “A” recommendation.

Neural tube defects are caused by a failure of the embryonic neural tube to close completely, which should occur in the first 28 days following fertilization. This is why folic acid is most effective if started at least 1 month before conception and continued for the first 2 to 3 months of pregnancy.

An estimated 3000 neural tube defects occur each year in the United States. Spina bifida, anencephaly, and encephalocele occur at respective rates of 3.9, 2.5, and 1.0 in 10,000 live births in the United States, which totals 7.4/10,000.³

Folic acid, if taken before and during pregnancy, can prevent about half of neural tube defects; if taken only during pregnancy, it prevents about one-third. If 50% of neural tube defects could be prevented with folic acid supplements, the number needed to treat (NNT) to prevent 1 case is about 3000.⁴

The case for supplementation. The recommended daily dose of folic acid is between 0.4 mg (400 μg) and 0.8 mg (800 μg), which is contained in many multivitamin products. Certain enriched cereal grain products in the United States have been fortified with folic acid for more than 2 decades, but it is unknown whether women in the United States are ingesting enough of these fortified foods to provide maximum prevention of neural tube defects. There are no known harms to mother or fetus from folic acid supplementation at recommended levels.

Room for improvement. Only 20% to 40% of people who are pregnant or trying to get pregnant, and 5% to 10% of people with an unplanned pregnancy, take folic acid supplements. Half of all pregnancies in the United States are unplanned.⁴ This leaves a lot of room for improvement in the prevention of neural tube defects.

An important recommendation, even if you don’t see the results. The NNT to prevent a case of neural tube defect is high; most family physicians providing perinatal care will not prevent a case during their career. And, as with most preventive interventions, we do not see the cases prevented. However, on a population-wide basis, if all women took folic acid as recommended, the number of severe birth defects prevented would be significant—making this simple recommendation worth mentioning to those of reproductive age.

The US Preventive Services Task Force (USPSTF) recently published a draft recommendation on the use of folic acid before and during pregnancy to prevent fetal neural tube defects.¹ This reaffirmation of the 2017 recommendation states that all persons planning to or who could become pregnant should take a daily supplement of folic acid.^1,2 This is an “A” recommendation.

Neural tube defects are caused by a failure of the embryonic neural tube to close completely, which should occur in the first 28 days following fertilization. This is why folic acid is most effective if started at least 1 month before conception and continued for the first 2 to 3 months of pregnancy.

An estimated 3000 neural tube defects occur each year in the United States. Spina bifida, anencephaly, and encephalocele occur at respective rates of 3.9, 2.5, and 1.0 in 10,000 live births in the United States, which totals 7.4/10,000.³

Folic acid, if taken before and during pregnancy, can prevent about half of neural tube defects; if taken only during pregnancy, it prevents about one-third. If 50% of neural tube defects could be prevented with folic acid supplements, the number needed to treat (NNT) to prevent 1 case is about 3000.⁴

The case for supplementation. The recommended daily dose of folic acid is between 0.4 mg (400 μg) and 0.8 mg (800 μg), which is contained in many multivitamin products. Certain enriched cereal grain products in the United States have been fortified with folic acid for more than 2 decades, but it is unknown whether women in the United States are ingesting enough of these fortified foods to provide maximum prevention of neural tube defects. There are no known harms to mother or fetus from folic acid supplementation at recommended levels.

Room for improvement. Only 20% to 40% of people who are pregnant or trying to get pregnant, and 5% to 10% of people with an unplanned pregnancy, take folic acid supplements. Half of all pregnancies in the United States are unplanned.⁴ This leaves a lot of room for improvement in the prevention of neural tube defects.

An important recommendation, even if you don’t see the results. The NNT to prevent a case of neural tube defect is high; most family physicians providing perinatal care will not prevent a case during their career. And, as with most preventive interventions, we do not see the cases prevented. However, on a population-wide basis, if all women took folic acid as recommended, the number of severe birth defects prevented would be significant—making this simple recommendation worth mentioning to those of reproductive age.