Methylfolate vs folic acid: who needs it?
Most people don’t. Methylfolate and folic acid raise your folate about as well. But if you could get pregnant, only one has been tested for preventing spina bifida. It’s the plain one.
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Do I need methylfolate instead of folic acid?
Probably not. Methylfolate, also sold as 5-MTHF, is the main form of folate in your blood. Folic acid is the man-made form of vitamin B9. Your body changes it into methylfolate.
Skipping that step sounds better. But a 2024 review found methylfolate may absorb a little better at first, and the gap evens out over hours or days. At the same dose, both lift the folate in your red blood cells.
Think of two keys to the same door. One comes ready cut. The other gets cut on the way in. Both open the door. So the real question is which key has been tested for your job.
| Question | Folic acid | Methylfolate (5-MTHF) |
|---|---|---|
| What is it? | Man-made vitamin B9 | The main form of folate in blood |
| Raises your folate? | Yes | Yes, about as well at the same dose |
| Tested for preventing spina bifida? | Yes, in trials | No published trials |
| In the NHS pregnancy advice? | Yes, 400 micrograms a day | Not named |
Sources: NHS; Nutrients review 2024
Could you get pregnant? Read the next section. If not, a varied diet usually covers you (see food below).
Which folate should I take if I could get pregnant?
The NHS says take the plain one, 400 micrograms of folic acid every day, while trying. Ideally start 3 months before, or as soon as you find out. Keep going until 12 weeks pregnant.
It lowers the chance of spina bifida and other problems with the baby’s brain or spine. The 2024 review found no published trials of methylfolate for this.
This is for anyone who could get pregnant, not only those trying: about half of UK pregnancies are unplanned.
A GP can prescribe a higher 5mg dose if you’re planning a pregnancy or under 12 weeks pregnant and:
- you or the baby’s father has a neural tube defect, or a relative with one
- you had a previous pregnancy affected by one
- you have diabetes
- you have a blood condition such as sickle cell anaemia or thalassaemia
- you take medicine for epilepsy or HIV
Pregnant and eyeing a multivitamin with folic acid? Check with a doctor or pharmacist first. More on timing in folic acid for women.
Does MTHFR mean I need methylated vitamins?
“Methylated” on a label means the vitamin comes in its methyl form, such as methylfolate. The usual reason given for them is a gene called MTHFR. Its enzyme, a body chemical that speeds up a reaction, makes methylfolate from other folate.
One common version of the gene, called C677T, is a variant. The same review found 400 micrograms of folic acid cuts neural tube defects “regardless of MTHFR” variants.
The US public health agency advises 400 micrograms of folic acid for women who may get pregnant, including those with C677T. US obstetricians don’t advise routine testing for it.
So if you could get pregnant, an MTHFR result doesn’t change the advice: 400 micrograms of folic acid a day. Our MTHFR guide explains what the variant does and doesn’t do.
Is methylfolate safer if my B12 is low?
Nobody knows yet. What is known: folic acid above 1mg a day can mask the symptoms of low B12. If it isn’t spotted and treated, low B12 can eventually damage the nervous system.
The NHS says 1mg or less a day of folic acid is unlikely to cause any harm. The usual 400 micrograms is 0.4mg.
- 1 mg or belowNHS: unlikely to cause harm.
- Above 1 mgNHS: can mask low B12. 5mg is on prescription.
Sources: NHS; NHS pregnancy
Some experts have proposed that methylfolate is less likely to hide low B12. That’s a theory, not tested advice.
Before treating low folate, your GP checks your B12 first. Ask for both to be tested together. See the folate blood test and signs of low B12.
Can I get enough folate from food?
Most adults can. You need 200 micrograms of folate a day, and the NHS says most people get it from a varied, balanced diet.
Easy ways to get folate from food
- Add broccoli or brussels sprouts to a meal.
- Eat leafy greens, such as cabbage, kale, spring greens or spinach.
- Add peas, chickpeas or kidney beans to stews and salads.
- Pick a breakfast cereal fortified with folic acid.
- Eat liver now and then, but avoid it if you’re pregnant.
- Limit alcohol if you take folic acid. It can affect how well it works.
Sources: NHS; NHS: folic acid
From 13 December 2026, UK non-wholemeal wheat flour must have folic acid added. Wholemeal flour isn’t included.
Eat few of these foods? A blood test shows where you stand. See low folate levels.
When to speak to a GP
The NHS says see a GP if you have signs of low B12 or folate. Book an appointment if:
- You feel weak or tired, short of breath, or have headaches, palpitations (a racing or pounding heartbeat), indigestion, loss of appetite or diarrhoea.
- You have a sore or red tongue, sometimes with mouth ulcers, or problems with your vision, memory, understanding or judgement.
- You have numbness, pins and needles, muscle weakness, problems with balance and coordination, low mood, anxiety or confusion, or you can’t control your bladder or bowels.
- You’re planning a pregnancy and any of the 5mg reasons above apply to you.
- You’ve taken more multivitamins than the label says. Get help from NHS 111.
Never stop or change a prescribed medicine without your prescriber. Too much folate on a test? See high folate levels.