Folic Acid and Pregnancy
NICE guideline [NG247] Maternal and child nutrition: nutrition and weight management in pregnancy, and nutrition in children up to 5 years. Published: Jan 2025.
NICE CKS Pre-conception – advice and management: Scenarior: Pre-conception advice for all women. Last revised: Jun 2025.
Guidelines
Overview of Pregnancy and Supplements
NICE recommends taking the Healthy Start vitamins (free supplements provided by the NHS to eligible pregnant women) that contain:
- Folic acid 400 micrograms
- Vitamin C 70mg
- Vitamin D 400 IU
Vitamin A supplementation is not recommended during pregnancy.
Pregnant women should avoid taking supplements containing vitamin A (retinol) and should not eat liver or liver products, as these contain high levels of vitamin A. Excess vitamin A during pregnancy has potential teratogenic effects.
Folic Acid and Pregnancy
Indications
- ALL women who are planning pregnancy → take before attempting
- ALL women who are already pregnant → take ASAP
It is best practice to start folic acid BEFORE conception.
This is because the neural tube closes within the first 4 weeks of gestation, starting folic acid only after a +ve pregnancy test may miss this crucial window for neural tube defect prevention.
Duration
Folic acid should be taken from whenever started (ideally pre-conception) until 12 weeks of pregnancy
Folic Acid Doses
Standard dose: folic acid 400 micrograms (not mg!) daily
High-dose folic acid 5mg daily should be offered to those at increased risk of having a baby with neural tube defect or other congenital malformation:
- Partner with neural tube defect
- Personal family history of neural tube defect
- Previous pregnancy with a neural tube defect
- Diabetes (1 and 2)
- Sickle cell anaemia and thalassaemia
- Taking anti-epileptic and HIV medicines
Overweight / obesity used to be an indication for high-dose folic acid. However, this alone is no longer an indication.
Reassure anyone with a body mass index (BMI) of 25 kg/m2 or more who is planning to become pregnant or is in the first 12 weeks of pregnancy that they do not need to take more than 400 micrograms of folic acid a day, unless they have any of the factors listed in recommendation 1.1.5.
References
Original Guideline