Should I take Methylfolate to prevent neural tube defects?

Dear Professor Winston,

There are increasing amounts of articles online and books that say that taking Methylfolate is superior to taking Folic Acid pre-conception and during pregnancy. The reason given is that a high percentage of the population have a genetic mutation which means they cannot efficiently absorb folic acid but have no problem with Methylfolate. However, I have recently read from other sources that this is bad advice and [that] Folic Acid is the only proven supplement to help prevent neural tube defects irrelevant of any mutation. What are your thoughts/current understanding on this? I have no way of knowing if I have the mutation and previously I had reasoned to take the Methylfolate as an ‘all bases covered’ which I have been doing pre-conception (I am not yet pregnant). But I am now worried that has been a waste of time and a mistake. Do I need to switch to Folic Acid in order to help prevent neural tube defects?
I am 30 years old, non smoker and don’t drink, healthy weight, no history of neural tube defects in my family; what dosage would you say was optimal when preparing the body for conception?

Kind regards,

N

Dear N,

I think it possibly doesn’t matter that much but folic acid is a proven medication so that is what I would normally have my patients take.

Best wishes
Robert Winston