Take folic acid. It's probably the most consistent piece of advice women get when they start thinking about pregnancy. From their GP, from the pharmacist, from every prenatal on the shelf.
And look, the intention behind it is right. Folate is critical in early pregnancy.
And honestly, the bit that almost never comes up is that folic acid and folate aren't the same thing. For a lot of women, that gap matters more than they'd expect.
So what's the difference?
Folic acid is the synthetic version. The body can't use it straight away. It goes through a conversion process first, ending up as 5-MTHF, which is the active form. One of those conversion steps depends on an enzyme called MTHFR, and this is the part that catches a lot of people out.
Somewhere between 30 and 50% of Australians carry a variant of that gene that slows the whole process down. One copy and the enzyme runs at around 65%. Two copies and you're looking at roughly 30%.
No symptoms. No test for it unless you go looking. Most people find out incidentally, usually through fertility investigations or after recurrent pregnancy losses.
So if your MTHFR enzyme is running at 30%, a chunk of the folic acid you're taking every day isn't converting. It's just sitting there unmetabolised.
Why this matters before you even have a positive test
The neural tube closes around day 28. That's your baby's brain and spinal cord forming, usually before most women have taken a test. Folate needs to already be there at adequate levels for that window. If conversion has been impaired and levels aren't where they need to be, it can influence the viability of the pregnancy.
What about all the folic acid research?
Those trials were done a long time ago. You couldn't run the same study today. Withholding folate from pregnant women wouldn't get through an ethics review. So the reason there's less direct trial data on methylfolate specifically isn't a question of whether it works.
The original research on folic acid and neural tube defect prevention is solid and still stands. But methylfolate skips the conversion entirely. It's already active, which means it works the same way for everyone, regardless of which MTHFR variant they carry or don't carry.
Worth knowing for men too. MTHFR variants affect both partners and folate status influences sperm health.
Do you need to test for MTHFR before trying to conceive?
Most people don't need to test. It typically comes up after recurrent losses, as one piece of a bigger picture. For everyone else, choosing a prenatal that already contains methylfolate covers it without needing a result first.
What to look for
On the folate line of any prenatal label, look for levomefolate glucosamine, L-methylfolate or 5-MTHF. Both Nuri's Prenatal Support [Her] and Prenatal Support [Him] use levomefolate. It's one of the decisions we feel most strongly about in the formulation.
This is general information only. If you have a history of recurrent pregnancy loss or are on other medications, please speak with your GP about your specific folate needs.
