TABLE 1.

Recommendations for prenatal FA supplementation in Canada and the United States¹

		Recommended FA dose and definition of NTD risk groups
		Low risk		Intermediate/moderate risk		High risk
Organization	Year	Dose, μg	Definition	Dose, μg	Definition	Dose, μg	Definition
US CDC (5)	1991	—	—	—	—	4000	Women who have had a pregnancy resulting in an infant or fetus with an NTD
US Public Health Service (29)	1992	400	All women of childbearing age in the United States who are capable of becoming pregnant	—	—	—	—
Society of Obstetricians and Gynaecologists of Canada (7, 30–32)	1993	400	Women of childbearing age and low NTD risk planning a pregnancy2	1000–4000	No NTD history, but have T1D, epilepsy treatment, first-degree relative with NTD, FA antagonist use	4000	Previous pregnancy with NTD
	2003	400–1000	Women of childbearing age and low NTD risk planning a pregnancy	4000–5000	No NTD history, but have T1D, epilepsy treatment, first-degree relative with NTD, FA antagonist use	4000–5000	Previous pregnancy with NTD
	2007	400–1000	No personal health risks, planned pregnancy, good compliance	5000	Epilepsy, T1D, obesity with BMI > 35 kg/m2, family history of NTD, high-risk ethnic group (e.g., Sikh); history of poor compliance with medications, variable diet, no consistent birth control, possible teratogenic substance use (alcohol, tobacco, recreational nonprescription drugs)	5000	Previous pregnancy with NTD or other potentially folate-responsive congenital anomaly
	2015	400	Women or male partners with no personal or family history of FA-sensitive birth defects	1000–4000	First or second family history of NTD, personal history of other folate-sensitive congenital anomalies, maternal diabetes, teratogenic medications, maternal GI malabsorption conditions	4000	Personal history of NTD or previous NTD pregnancy in either partner
Health Canada and the Public Health Agency of Canada (6, 33)	1993	—	As early as possible, women planning a pregnancy should consult physician about FA supplements	—	—	—	Previous NTD pregnancy, refer to physician
	1995–2018	4003	All women who could become pregnant	—	Refer to health care provider	—	Refer to health care provider

¹FA, folic acid; GI, gastrointestinal; NTD, neural tube defect; T1D, type 1 diabetes.

²Women should consider a minimum of 400 μg FA or the adequate dietary equivalent according to Canada's Food Guide to Healthy Eating.

³As part of a multivitamin containing 400 μg FA.