Also known as: Folate, Folic acid, 5-MTHF, Methylfolate, L-methylfolate, Quatrefolic
VitaminsStrong evidence
Essential for DNA synthesis and cell division, and one of the few nutrients with a specific public health recommendation attached. Folate and folic acid are not the same thing, and the difference matters.
Typical dose
200.0–400.0 mcg per day
Any time, with or without food; take alongside B12
What it is
Folate is the naturally occurring form found in food — the name comes from the Latin for leaf, reflecting its abundance in green vegetables. Other good sources include legumes, liver, asparagus and citrus.
Folic acid is the synthetic form used in supplements and food fortification. It is more stable and better absorbed than food folate, which is precisely why it is used, but the body must convert it through several steps before it becomes usable.
5-MTHF, or methylfolate, is the already-active form. It bypasses the conversion steps entirely, which is the argument for choosing it — particularly since a substantial share of people carry gene variants that make that conversion less efficient. It costs more, and for most people plain folic acid works perfectly well.
How it works
Folate is central to one-carbon metabolism, donating carbon units for the synthesis of DNA and RNA. That makes it indispensable wherever cells are dividing rapidly, which is why requirements rise sharply during periods of growth.
It also works alongside B12 to convert homocysteine back into methionine, feeding the methylation cycle that underpins gene regulation and neurotransmitter production.
That partnership with B12 is where a genuine complication arises. High folate intake can correct the blood picture of low B12 while leaving the underlying B12 shortfall unaddressed and progressing. This is the main reason folic acid supplements are usually paired with B12, and it is a real consideration rather than a marketing one.
What the evidence shows
Folate's essentiality is beyond question. The public health recommendation that women take 400 micrograms of folic acid daily before conception and through the first twelve weeks of pregnancy is among the best-evidenced supplement recommendations in existence, and is UK government advice.
Folate supplementation reliably lowers homocysteine, which is well established as a biochemical effect. Whether lowering it produces downstream benefit has been tested in large trials with generally disappointing results, which is worth knowing before paying extra for methylation-focused products.
For energy or performance in people with adequate intake, there is no meaningful evidence of benefit.
Dosing
Reference intake is around 200 micrograms daily for adults. The specific recommendation for women who could become pregnant is 400 micrograms of folic acid daily, starting before conception rather than after, since the relevant window is very early.
Supplemental intake above 1,000 micrograms daily is generally advised against, largely because of the interaction with B12 status described above.
If choosing methylfolate over folic acid, note that doses are not equivalent milligram for milligram and that it is considerably more expensive. For most people folic acid is entirely adequate. Whichever you take, pair it with B12.
At a glance
Common forms
Folic acid, L-5-MTHF (methylfolate), Quatrefolic, Food folate, Within B-complex
Half-life / duration
Body stores last several months; status changes over weeks
Timing
Any time, with or without food; take alongside B12
Competition status
Permitted — not on the WADA Prohibited List
Category
Vitamins
Safety and side effects
Folate from food carries no upper limit and no safety concern. Folic acid from supplements and fortified food has a tolerable upper intake of 1,000 micrograms daily for adults.
That limit exists chiefly because high folic acid intake can mask a developing B12 shortfall, allowing it to progress unnoticed. Taking the two together sidesteps this, which is why most sensible products combine them.
Speak to your doctor before use if you take regular medication, since several medicines interact with folate handling.
Who should avoid it
Do not exceed 1,000 micrograms of supplemental folic acid daily without medical advice. Take alongside B12 rather than alone, since high folate intake can mask a developing B12 shortfall. Speak to your doctor before use if you take regular medication or are under medical care.
This entry is provided for information only. Food supplements should not be used as a substitute for a varied and balanced diet and a healthy lifestyle. Consult a qualified healthcare professional before use if you are pregnant, breastfeeding, taking medication or under medical supervision.
