If there is one supplement every woman planning a pregnancy should know about, it is folic acid. This simple B vitamin dramatically reduces the risk of serious problems in a baby's brain and spine — but only if it is on board before and in the earliest weeks of pregnancy. Here is what to take, how much, and when.

Why folic acid matters so much

Folic acid helps the body make healthy red blood cells, and in early pregnancy it plays a critical role in forming the baby's neural tube — the structure that becomes the brain and spinal cord. Taking folic acid greatly reduces the risk of neural tube defects (NTDs) such as spina bifida.1

Here's the catch: the neural tube forms in the first few weeks of pregnancy — often before you even know you are pregnant. That is why supplementation should ideally begin before conception, not after the positive test.

How much, and for how long

  • The guideline dose is 400 micrograms (mcg) daily, starting at least one month before trying to conceive and continuing until the end of the 12th week of pregnancy.1,2
  • In Sri Lanka, folic acid is dispensed as 1 mg tablets, so in practice most women here take one 1 mg tablet daily — this comfortably covers the guideline amount and is the standard local practice. Either way, the message is the same: start before pregnancy and take it every day.
  • If you are already pregnant and haven't been taking it, start straight away — it still helps in the first trimester.
  • After 12 weeks, the folic acid job is largely done; many women simply continue their pregnancy multivitamin, which typically contains 400 mcg of folic acid, for the rest of pregnancy.

Who needs the higher 5 mg dose?

Some women need a higher, prescription dose of 5 mg daily, started before conception. Your doctor may advise this if you have a higher risk of a neural tube defect, for example:1,2

  • Diabetes
  • Obesity (BMI of 30 or more)
  • A previous pregnancy affected by a neural tube defect, or a family history of NTDs
  • You take anti-epileptic medicines
  • Certain blood conditions such as thalassaemia

If any of these apply to you, speak to us before trying to conceive so the right dose can be started early.

What about food?

Folate-rich foods — leafy green vegetables, citrus fruits, beans, and fortified cereals — are a healthy part of any pregnancy diet, and we encourage them. But be clear on one point: diet alone cannot reliably provide enough folic acid to prevent neural tube defects. The supplement is essential, and food supports it — not the other way around.1

You may also see supplements containing L-methylfolate, a form of folate marketed as more easily absorbed. For preventing neural tube defects, standard folic acid is the form backed by decades of evidence and recommended by guidelines — there is no need to pay more for alternatives unless your doctor specifically advises one for you.

The takeaway

Folic acid is the simplest, cheapest, most powerful thing you can do for your future baby's health: 400 mcg a day by guideline — in Sri Lanka, practically, one 1 mg tablet daily — from at least a month before conception until the end of week 12, and a 5 mg prescription dose if you are higher-risk. Planning a pregnancy? Start today, and come and see us at Sugabi Clinic for advice tailored to you.

References

  1. NHS. Folic acid: How and when to take it [Internet]. London: NHS; [cited 2026 Jul 21]. Available from: https://www.nhs.uk/medicines/folic-acid/how-and-when-to-take-folic-acid/
  2. NHS. Pregnancy vitamins and supplements [Internet]. London: NHS; [cited 2026 Jul 21]. Available from: https://www.nhs.uk/pregnancy/keeping-well/pregnancy-vitamins-and-supplements/
  3. National Institute for Health and Care Excellence. Maternal and child nutrition (NG247) [Internet]. London: NICE; 2025 [cited 2026 Jul 21]. Available from: https://www.nice.org.uk/guidance/ng247