Folic Acid Before Pregnancy: Why Timing Is the Whole Point

What is folic acid and why does it matter before pregnancy?

Folic acid (Folic Acid) is the synthetic form of vitamin B9, which occurs naturally in food as folate (Folate). The body uses it to build DNA and support rapid cell division, which makes it especially critical during the earliest weeks of embryo development, when cells are multiplying at the fastest rate they will ever reach.

Its protective role is one that simply cannot be replicated once a pregnancy is confirmed. The neural tube (Neural Tube), the embryonic structure that becomes the brain and spinal cord, begins forming and closing between day 22 and the end of week 4 of pregnancy. At that point, most women are not yet aware they are pregnant and have not started any supplement.

If folate levels in the body are insufficient during this narrow window, the neural tube may fail to close completely. The result is a group of serious conditions: spina bifida (Spina Bifida), in which the spine and spinal cord do not form properly, or anencephaly (Anencephaly), the most severe form, in which major parts of the brain do not develop.

When exactly should a woman start taking folic acid?

The clear international recommendation is to start folic acid at least one month before trying to conceive, and ideally three months before. This lead time allows the body to build adequate folate levels in red blood cells, which reflect stores accumulated over the previous two to three months.

The US Preventive Services Task Force reaffirmed this recommendation in 2023 after a comprehensive systematic review. Importantly, the recommendation applies to all women who are capable of becoming pregnant, not only those actively planning a pregnancy, because roughly half of all pregnancies worldwide are unplanned.

The practical problem across the region is that many women start folic acid only after a positive pregnancy test, or even after a first antenatal appointment. A 2024 study published in the African Journal of Reproductive Health in Jazan, Saudi Arabia, found that a significant proportion of women did not know that folic acid should be taken before pregnancy. A 2012 study of Lebanese women of childbearing age, published in Maternal and Child Health Journal, found that while awareness of folic acid was reasonable, fewer than half were taking it preconceptionally. Knowledge and behaviour remain two different things.

What is the correct dose, and when should it be higher?

For women at average risk, the recommended dose is 400 micrograms (0.4 mg) per day. This amount is found in most prenatal multivitamins and in dedicated folic acid tablets sold at pharmacies without a prescription. It is important to check the label, because the folate content of multivitamins varies widely between brands.

The dose rises to 5 milligrams per day for women with specific risk factors. These include: a previous pregnancy affected by a neural tube defect, a personal or partner history of a neural tube defect, taking antiepileptic medication regularly, a body mass index above 30, poorly controlled diabetes, or a malabsorption condition such as coeliac disease (Coeliac Disease). This higher dose requires a prescription in most countries and is not interchangeable with the standard supplement available over the counter.

If you are unsure which category you fall into, a short conversation with your doctor or pharmacist before you start trying to conceive will clarify things quickly. The decision takes a few minutes and the benefit can be measured in a lifetime.

Why is neural tube defect risk higher in some regional populations?

A review of neural tube defect biology published in Annual Review of Neuroscience in 2014 by Greene and Copp confirms that these defects are among the most common serious birth defects worldwide, and that rates are higher in populations without systematic fortification of staple foods with folate.

In our region, several additional factors elevate the risk. Consanguineous marriages, which are relatively common, increase the likelihood of inheriting variants in the MTHFR enzyme that reduce the body's ability to convert folic acid into its active form. When the conversion pathway is less efficient, standard doses may not achieve the same cellular protection, and higher doses or the active form of the vitamin may be more appropriate.

Food fortification with folic acid, a policy shown to substantially reduce neural tube defect rates in countries that have adopted it, is not widespread across most of the Arab world. This places a greater burden on individual supplementation. Without a population-level fortification programme, the only reliable way to ensure adequate folate during the critical window is through a personal supplement taken before conception.

Which foods are richest in folate and can diet replace a supplement?

Natural folate is found in dark green leafy vegetables like spinach, molokhia and parsley, in legumes like lentils, chickpeas and broad beans, in eggs and in liver. These are foods that appear regularly in Arab cuisine, and building them into your meals consistently is worthwhile both before and during pregnancy.

However, natural folate from food alone is unlikely to be sufficient to reliably achieve the cellular concentrations that protect against neural tube defects. Natural folate is less stable than the synthetic form, losing a meaningful proportion of its content during cooking. Synthetic folic acid in supplements is absorbed more consistently and maintains its potency over time. This is why all international guidelines recommend a supplement alongside a folate-rich diet, not instead of it.

Some countries have demonstrated dramatic reductions in neural tube defect rates after mandating folic acid fortification of flour. In settings where this policy is absent, the individual supplement becomes even more important, and the responsibility for achieving adequate levels rests entirely with the woman and her doctor.

Is there a different form of folate for women with MTHFR variants?

Standard folic acid must be converted by the MTHFR enzyme into its active form, 5-methyltetrahydrofolate (5-MTHF), before cells can use it. A subset of women carry genetic variants that reduce this enzyme's efficiency. This is more common in populations with higher rates of consanguinity.

For these women, supplements containing the active form directly, marketed as methylfolate or 5-MTHF (Methylfolate), bypass the conversion step. A 2024 narrative review in Nutrients examined the evidence comparing folic acid with 5-MTHF and concluded that both are effective for neural tube defect prevention, but that the active form may offer advantages in women with impaired conversion.

Routine MTHFR testing is not recommended for all women, and having the variant does not automatically mean supplementation is failing. If you have a personal or family history of neural tube defects, or if a previous pregnancy was affected, discuss this with your doctor. It is a conversation worth having rather than a reason to delay starting.

In some countries in the region, MTHFR genetic testing is available through private laboratories. If you choose to have this test, do not wait for the result before starting folic acid. The test informs which form may be optimal; it does not change the fundamental recommendation that supplementation should begin before conception.

What other benefits does folic acid offer during pregnancy?

Research suggests that adequate folate around the time of conception and in the first trimester may reduce the risk of early miscarriage, megaloblastic anaemia from folate deficiency, and certain congenital heart defects and cleft lip or palate. These benefits are separate from neural tube defect protection and add further weight to the case for starting supplementation early.

Folic acid does not replace the other micronutrients that matter in pregnancy. Iron, vitamin D, calcium and iodine each play distinct roles at different stages. But folic acid has a time-sensitive advantage that none of the others share: its critical protective action happens before any other supplement would normally be prescribed.

Some research has also investigated a possible link between preconceptional folate and a reduced risk of autism spectrum conditions in offspring. This evidence is not yet at the level required for official guidelines to cite it as a standalone reason to supplement, but it adds to the general picture of benefit rather than competing with the established neural tube defect argument.

Practically speaking, most prenatal multivitamins combine folic acid with iron, vitamin D and other micronutrients. If the folic acid content on the label shows 400 micrograms per tablet, this is sufficient for standard risk. Read the label carefully, because not all multivitamins contain the same amount, and some marketed for general use contain as little as 200 micrograms of folate, which is below the recommended level for pregnancy.

What if you just found out you are pregnant and have not started folic acid?

The answer is simple: start now. Do not lose time feeling guilty about the delay. Even if the most sensitive period for neural tube closure has already passed, folic acid continues to support nervous system development, cell replication and red blood cell production throughout the first trimester and beyond. There is value in starting at any point.

The 2023 JAMA systematic review confirmed that supplementation through the full first trimester and beyond carries benefit, and that women who begin after conception still receive meaningful protection for aspects of fetal development that are not yet complete. Every week of the first trimester matters.

Contact your doctor or midwife as soon as possible. Tell them the date of your last period so they can calculate your gestational age precisely. They may recommend additional ultrasound scans later in the first trimester to check for structural development, and knowing your folic acid history is a piece of information they will want.

It is also worth remembering that many women who never took folic acid before pregnancy have had completely healthy babies. The absence of supplementation raises risk, it does not make a poor outcome inevitable. What you can control is what happens from today forward, and starting now is always better than not starting at all.

Sources

• Viswanathan M, Urrutia RP, Hudson KN et al: Folic Acid Supplementation to Prevent Neural Tube Defects: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force, JAMA, 2023
• Samaniego-Vaesken ML, Morais-Moreno C, Carretero-Krug A et al: Supplementation with Folic Acid or 5-Methyltetrahydrofolate and Prevention of Neural Tube Defects: An Evidence-Based Narrative Review, Nutrients, 2024
• Greene ND, Copp AJ: Neural tube defects, Annual review of neuroscience, 2014
• Dobie G, Al-Hazazi N, Nahari M et al: Assessment of awareness, knowledge, and usage of folic acid among females in Jazan Region, Saudi Arabia, African journal of reproductive health, 2024
• Nasr Hage C, Jalloul M, Sabbah M et al: Awareness and intake of folic acid for the prevention of neural tube defects among Lebanese women of childbearing age, Maternal and child health journal, 2012
• US Preventive Services Task Force, Barry MJ, Nicholson WK et al: Folic Acid Supplementation to Prevent Neural Tube Defects: US Preventive Services Task Force Reaffirmation Recommendation Statement, JAMA, 2023
• World Health Organization: WHO recommendations on antenatal care for a positive pregnancy experience, WHO, 2016