Folic acid/vitamin B9 and conception: what you need to know

Folic acid is the common name given to vitamin B9, a vitamin our body cannot produce on its own. It is the pregnancy food supplement essential.

However, it is a term that is used somewhat loosely, as "folic acid" actually means " vitamin B9 of synthetic origin", meaning it is manufactured in laboratories, as opposed to folate, the "naturally occurring vitamin B9" found in certain foods.

To avoid confusion, throughout the rest of this article we will use "folic acid" to refer to synthetic vitamin B9, "folate" to refer to naturally occurring vitamin B9, and "vitamin B9" to refer to this nutrient without distinction.

In summary

• When trying to conceive, ANSES recommends 400 µg of folic acid per day, ideally 2 to 3 months before trying for a baby.
• This early action is essential, as the neural tube closes as early as day 28 of pregnancy, often before a positive test result.
• Supplementation started before conception may reduce the risk of neural tube closure defects by 50 to 70% (WHO).
• Around 33% of Europeans carry a variation of the MTHFR gene that reduces the absorption of synthetic folic acid.
• For these individuals, the methylated form 5-MTHF is better absorbed. This article is aimed at women trying for a baby.

Updated on 5 May 2026

Vitamin B9 is involved in many functions in our body: DNA and RNA synthesis, cell growth and division, amino acid/protein metabolism…

A vitamin B9 insufficiency or deficiency can lead to problems with cell division and protein synthesis — processes that are absolutely vital. In the event of insufficiency or deficiency, the cells with the greatest capacity for rapid division are the first to be affected: red blood cells, cells of the digestive system, the embryo… potentially leading to megaloblastic anaemia, deterioration of the digestive tract, and slower foetal growth and development during pregnancy…

Pregnancy and folic acid: why is it so important for conception and during pregnancy?

It has been observed that a vitamin B9 insufficiency or deficiency could lead to neural tube defects in the baby (congenital malformations of the brain, spine and/or spinal cord, including the well-known spina bifida), which forms by day 28 of pregnancy — in other words, at a time when you may not yet know you are pregnant.

A vitamin B9 deficiency may also be a possible contributing factor in recurrent miscarriages.

Please note that folate supplementation has a protective effect against neural tube defects only before the fourth week of pregnancy. This is why it is recommended to supplement with vitamin B9 ahead of conception — ideally 1 to 3 months before stopping your contraception — to allow your folate reserves to reach a protective level. It is therefore important to ensure that your women's fertility supplement contains it.

On the father-to-be's side, vitamin B9 also contributes to sperm quality: it plays a role in sperm motility and morphology. The journey to parenthood can therefore be an opportunity for both partners to take action together, through a diet rich in folates or a suitable supplement.

The best sources of vitamin B9

Wheat germ: 350 µg per 100g Animal livers: 300 µg per 100g (caution during pregnancy due to teratogenic retinol content) Legumes (lentils, chickpeas, white beans): for example, lentils contain 71 µg of folates in active 5-MTHF form and raw chickpeas 125 µg per 100g Green leafy vegetables (lettuce, spinach, watercress, cabbage…): 100 µg per 100g for kale, of which half is in active form Dried nuts (walnuts, hazelnuts…): 200 µg in 100g of hazelnuts Broccoli: 100 µg per 100g, of which 67% is in active 5-MTHF form Citrus fruits (lemon, orange…): nearly 100% of folates in active form Berries (strawberry, raspberry, cherry): nearly 100% of folates in active form — for example, strawberries contain 79 µg of active folates per 100g

Requirements during pregnancy

As a guide, it is recommended to consume 600 micrograms of vitamin B9 per day during pregnancy or when trying to conceive [1]. This is why it is often advised to take 400 micrograms in supplement form, in addition to a balanced diet.

A vitamin B9 deficiency can not only cause neural tube defects in babies, but also later malformations such as urinary tract abnormalities, limb defects, abdominal wall defects, and cleft lip and palate. It can also lead to gestational hypertension in women [2][3]...

I've just found out I'm pregnant but I didn't take a B9 supplement before conceiving — what should I do? In the case of an unplanned pregnancy, if you have not taken vitamin B9 beforehand, it is advisable to start taking it as soon as you discover you are pregnant, to help prevent later malformations.

Folate does not hold up well to light or heat (it is unstable above 60 degrees). Between oxidation and cooking, some dietary folate is therefore lost by the time it is consumed. Folic acid, on the other hand, is more bioavailable — in other words, it is more easily absorbed into the bloodstream. One might therefore think that folic acid is the better choice.

However, once absorbed, it is folate that has the advantage over folic acid.

Many steps are needed for folic acid to become active

Folate only needs to undergo a single reaction to become usable by the body. This reaction is called methylation. It is a process by which a methyl group (one carbon atom and three hydrogen atoms) is added to a substrate such as a gene, an enzyme, a hormone, a neurotransmitter, a vitamin… in this case folate. The folate is thus "methylated" — it is then called methylfolate — and can enter the cells.

The majority of natural folates are already present in the active form of methylfolate, directly usable by the body, meaning methylation is not required.

Folic acid is not always converted into its active form

Folic acid must undergo many reactions before passing through methylation and finally being converted into methylfolate. However, these numerous reactions do not necessarily occur efficiently depending on your genetic profile, nutritional status or environment. If this is the case for you, folic acid supplementation will not be effective.

Folic acid can cause a folate deficiency!

Furthermore, because folic acid is structurally similar to folate, it can occupy folate receptors, preventing folate from accessing the cells. In other words, folic acid can not only potentially fail to be converted into a form usable by the body (methylfolate), but it can also block the use of folate, creating a cellular "deficiency" in folate — even if our body has plenty of it.

In short, it is a genuine shortcut for our body to deal with folate rather than folic acid, especially since folic acid can act as a parasite and block the use of folate. It is therefore preferable to supplement with folate rather than folic acid during pregnancy. Even better: did you know that you can supplement directly with methylfolate?

In short, it is a real shortcut for our bodies to deal with folate rather than folic acid, especially since folic acid can act as a competitor and block the use of folate. It is therefore preferable to supplement with folate rather than folic acid during pregnancy. Even better: did you know you can supplement directly with methylfolate?

Our pregnancy snack, Vanifique, contains folates derived from a spinach extract, naturally rich in 5-methyltetrahydrofolate, the directly active form! One snack provides 400 µg of folate. Another option: our vitamin B9 capsules !

Baby Bump, our multivitamin, with minerals, DHA and choline, contains folate in the form of 5-methyltetrahydrofolate (Quatrefolic®) at a daily dose of 400 µg per day.

Bump essentials and Bump powder, our pregnancy vitamins, also provide 400 µg of folate per day.

Elisabeth, 5/5 - 31/03/2026

« It is always a little difficult to gauge how effective vitamins are, but these ones seem to have worked as I had a calm and peaceful pregnancy. The folic acid they contain also helps the body to absorb iron taken alongside them. All of this while knowing you are consuming healthy, complete products! »

Once folate is activated — that is, once it has become methylfolate — it then becomes the starting point of the methylation cycle. 

The importance of the methylation cycle

A series of chemical reactions takes place, the purpose of which is to create a number of substances serving more than 200 functions, including: activation or deactivation of genes, DNA repair and maintenance, development of the central nervous system, synthesis of neurotransmitters and proteins, hormone regulation, hepatic detoxification, antioxidant production, regulation of immunity and cardiovascular functions, energy production… Methylation becomes even more active during pregnancy to support the development of the baby and the placenta.

The risks associated with a disrupted methylation cycle

One could even say that neural tube defects can be caused not only by insufficient or deficient vitamin B9, but also by a suboptimal methylation cycle. This is why it is important not to stop at vitamin B9, and to consider the "big picture" — that is, the methylation cycle. Beyond neural tube defects, sufficient levels of vitamin B9 and a well-functioning methylation cycle could help prevent tongue-tie in children, as well as postpartum depression, nausea and vomiting during pregnancy, reducing the risk of miscarriage…

Vitamin B12 needs folate in the methylation cycle

In order to give the "go-ahead" to the methylation cycle, the methyl group previously added to folate must be transferred to cobalamin (vitamin B12), which then becomes methylcobalamin. Methylcobalamin then transfers its methyl group to homocysteine to form methionine, which is used notably for DNA synthesis. Meanwhile, once stripped of its methyl group, folate is able to carry out its functions.

To summarise, vitamin B9 alone can do very little: it needs at least B12 to function and to allow other essential processes to take place. In other words, insufficient or deficient vitamin B12 renders vitamin B9 intake ineffective, and is therefore just as problematic as insufficient or deficient vitamin B9.

Other factors involved in the methylation cycle

In addition to sufficient amounts of vitamins B9 and B12, methylation requires cofactors — that is, "fuel" in the form of magnesium, zinc, choline, vitamin B6, vitamin D, vitamin C… These are therefore other nutrients that need to be present in adequate quantities.

Methylation is also compromised in the presence of toxins such as endocrine disruptors, heavy metals (mercury, arsenic, lead…), mycotoxins (toxins released by moulds)… hence the importance of reducing our exposure to toxic substances. It is also compromised by certain medications including antacids, by stress, and by a variation in the MTHFR gene (methylenetetrahydrofolate reductase) — the gene encoding the enzyme of the same name, which adds a methyl group to vitamin B9. It is estimated that this mutation is present in 40 to 60% of the population. Those affected are therefore unable to carry out the methylation cycle optimally.

When trying to conceive, to avoid issues with the methylation cycle, it is therefore better to: 

• Eating foods rich in folates (the majority of which are already in the form of methylfolate)
• Supplementing with the active form of folate, methylfolate (also known as MTHF or 5-MTHF), rather than folic acid, particularly if you have a variation of the MTHFR gene. 
• Supplementing with nutrients essential to methylation such as vitamins B12, B2, B6, magnesium, zinc, choline… which is why a well-formulated prenatal multivitamin complex is so useful. For B vitamins, it is preferable that these are also in their active or "methylated" form (methylcobalamin for B12, for example). 
• Eating foods rich in choline (eggs, red meat, poultry, fish, liver and other offal) or if you are vegetarian/vegan and your prenatal supplement does not contain choline, add a supplement of the type Choline Mama. 
• Avoiding methylation disruptors: reduce your exposure to endocrine disruptors, heavy metals, moulds or certain medications where possible, and as always, reduce stress. 

Be careful not to self-supplement — food supplements are not without effect, and can interfere with other supplements, foods and medications, or may not be suited to your personal situation, without even considering the need to choose them carefully and adjust dosages. It is therefore preferable to seek advice from a healthcare practitioner specialising in nutrition (such as a naturopath or nutritional therapist).

Sarah Mathis · Baby Bump · ⭐ 4/5 · 21/04/2026

« Delighted with this supplement. After 6 miscarriages and IVF stopping the protocol, I am taking Ovo+ and Baby Bump to improve natural fertility. I notice changes in my cycles and am seeing an improvement. Hoping these supplements help with conception. Very comprehensive and validated by the carers supporting me. Delighted with the folic acid in the Quatrefolic® form, suited to the 5-MTHFR gene mutation »