Folate explained — beyond pregnancy, and why the methyl form matters

Folate is most associated with one thing: pregnancy. That association is real, well-established, and responsible for decades of public health guidance. It is also only a slice of what folate does. For the other ~90% of adults who are not currently pregnant or planning to be, folate is still one of the B vitamins worth taking seriously — and the form you choose matters.

What folate is

Folate is vitamin B9, a water-soluble B vitamin essential for two processes the body does constantly: DNA synthesis (which happens every time a cell divides) and homocysteine metabolism (which is part of protein chemistry and cardiovascular physiology) ^[1].

"Folate" is actually an umbrella term covering a small family of related compounds:

• Dietary folate — the natural form found in leafy greens, legumes, and organ meats. Already in reduced forms, but chemically unstable, so often partially lost during cooking.
• Folic acid — the synthetic form. Stable, cheap to manufacture, added to fortified foods and most standard supplements. Requires enzymatic conversion by the body to become biologically active.
• 5-MTHF (L-methylfolate) — the biologically active form. The one the body actually uses. What folic acid has to be converted into before cells can do anything with it.

That conversion step is where the form discussion gets interesting.

The authorised EU/UK health claims

Folate has seven authorised claims under the EU and UK health-claim registers ^[2]:

• Folate contributes to normal amino acid synthesis.
• Folate contributes to normal blood formation.
• Folate contributes to normal homocysteine metabolism.
• Folate contributes to normal psychological function.
• Folate contributes to the normal function of the immune system.
• Folate contributes to the reduction of tiredness and fatigue.
• Folate has a role in the process of cell division.

Plus one specific to pregnancy: Supplemental folate intake increases maternal folate status. Low maternal folate status is a risk factor in the development of neural tube defects in the developing foetus — at 400 µg per day for at least one month before and up to three months after conception ^[3].

The last one is the familiar public-health message. The first seven are why folate matters for everyone else.

Why the form matters — MTHFR and methylfolate

Folic acid has to be converted into L-methylfolate before the body can use it. That conversion runs through an enzyme called methylenetetrahydrofolate reductase — MTHFR for short.

A sizeable fraction of the population carries a common genetic variant in the MTHFR gene (most notably MTHFR C677T). Estimates vary by population, but roughly 30-40% of adults in Europe carry at least one copy of a variant that reduces MTHFR enzyme activity. In people homozygous for C677T, enzyme activity can sit around 30% of normal.

Practically, that means:

• Folic acid still works for most of these people — their bodies eventually convert it, just more slowly.
• Unmetabolised folic acid can accumulate in people with slower conversion — a topic of ongoing research about whether this matters clinically at typical intake levels.
• Methylfolate bypasses the conversion step entirely. It is the form your cells use, delivered directly.

For everyone who does not have their MTHFR status tested (which is almost everyone), methylfolate simply sidesteps the question. Whether you are a "normal converter" or not, methylfolate is immediately usable. This is why the best B-complex formulations have moved to methylfolate over folic acid.

Extrafolate-S® — the specific form we use

Our B-Complex uses Extrafolate-S®, a specific branded form of L-5-methyltetrahydrofolate calcium salt developed by Gnosis by Lesaffre. Extrafolate-S is stabilised, well-absorbed, and the methylfolate form that appears in the most recent clinical research.

That is the difference between "folic acid" on a cheap multivitamin label and "L-5-MTHF (Extrafolate-S®)" on a quality B-complex label. Same claim on the tub; different molecule in the capsule.

Where your folate comes from

Dietary sources of folate — in roughly descending order of practical usefulness:

• Dark leafy greens — spinach, kale, rocket, watercress.
• Legumes — lentils, chickpeas, black beans. One of the most calorie-dense folate sources.
• Asparagus and broccoli.
• Liver — the most concentrated folate source in the animal kingdom.
• Avocado.
• Citrus fruit, especially oranges.
• Eggs.
• Fortified foods in the UK — some breakfast cereals, some flour (folic acid fortification is now mandatory in UK bread flour as of 2024).

Cooking destroys a portion of folate — typically 30-50%. Raw salads and lightly steamed vegetables preserve more of it than boiled ones.

Who tends to run low on folate

Populations where folate status is more often inadequate:

• Pregnant and breastfeeding women — demand rises, supply has to match ^[3].
• Women of childbearing age generally — because unplanned pregnancy is common, and folate needs to be adequate from conception, not when the test turns positive.
• People on certain medications — methotrexate, some anticonvulsants, sulfasalazine, and long-term metformin can all deplete folate.
• Heavy alcohol users — alcohol interferes with folate absorption and metabolism.
• People with coeliac disease or other malabsorption — common folate shortfall because the small intestine is where folate absorbs.
• Older adults — often paired with reduced B12 absorption (the two are linked in blood formation and need to be considered together).

How much folate, and how to take it

The EU NRV is 200 µg per day. The reference for pregnant women is higher — 400 µg supplemental, plus dietary ^[3].

In a B-complex, folate typically sits at 200-400 µg per capsule, often 200 µg for a daily supplement and 400 µg in prenatal-focused formulations. Our B-Complex provides 400 µg of L-5-MTHF as Extrafolate-S® per capsule.

Taking it: with food is slightly preferred (gentler on stomach); morning over evening (some people find B-complexes lightly stimulating); and consistently — folate status shifts over weeks, not days.

Always combined with B12. Folate and B12 are interdependent in blood formation. Supplementing folate without adequate B12 can mask the blood-cell changes that would otherwise flag a B12 deficiency — which is why quality B-complexes always include both ^[1].

Who should check with a doctor first

• Anyone on methotrexate. Methotrexate works by interfering with folate metabolism; supplemental folate interacts directly and needs to be coordinated with the prescribing doctor.
• Anyone with a history of epilepsy on certain anticonvulsants. Dose coordination matters.
• Pregnant women already on prenatal supplements — check the total folate across supplements to avoid double-dosing.
• Anyone with unexplained anaemia. Supplementing folate without a diagnostic workup can delay detection of B12 deficiency.

In practice

Folate is the B vitamin with the strongest pregnancy association and one of the broadest sets of authorised claims in the vitamin category. For most adults, its biochemical role in cell division, blood formation, homocysteine metabolism, and psychological function is reason enough to make sure dietary intake is adequate — and for most adults, a well-formulated B-complex with methylfolate (not folic acid) is the practical way to cover it.

Our B-Complex provides 400 µg of Extrafolate-S® L-5-MTHF alongside the other seven B vitamins — the form your cells use, paired with the B12 and B6 that sit in the same biochemical pathways.

References

1. NHS. B vitamins and folic acid. nhs.uk
2. European Commission. EU Register of Nutrition and Health Claims Made on Foods. ec.europa.eu
3. NHS. Vitamins, supplements and nutrition in pregnancy. nhs.uk

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