MTHFR: what the heck is it and why does it matter in your pregnancy?

Weekly pregnancy tip



8 Proven Shortcuts To A Healthy Pregnancy

it's free!
Protecting your personal information is of utmost importance to me

MTHFR is a hot topic right now, and if you haven’t heard of it yet, or still can’t quite wrap your head around it (other than to know that it makes a good science joke), this post will hopefully clarify a few things for you!

Basically, there’s a fairly complex set of reactions that happens inside of your body in an effort to move methyl groups around to where they are needed, which includes everything from neurotransmitter synthesis to detoxification to hormone production.

One element in this methylation pathway, homocysteine, builds up when it is unable to convert to methionine, a step that requires methylated B9 and methylated B12 (the “active” forms of these B-vitamins).

Converting folic acid (B9) to methylated folate requires an enzyme called MTHFR to add a methyl group to folic acid to make it usable by the pathway. However, an estimated 40% of North Americans have one or more mutations in the MTHFR gene that decreases their ability to methylate folate by 40-60%.

Poor methylation leads up to a build-up of homocysteine in the body, which in pregnancy is linked with recurrent miscarriage, infertility, pre-eclampsia and gestational diabetes, as well as an increased risk of spina bifida and autism in children. Definitely something you will want to avoid if possible!

So how might one approach this issue? It is possible to test for the MTHFR polymorphism (genetic mutation) through one’s care provider (testing is commonly done through Spectracell, or as part of a full genetic profile with

As an insurance policy, it is also possible to simply choose prenatal vitamins that include methylated folate/B9 (methyltetrahydrofolate) and methylated B12 (methylcobalamin), and of course to increase consumption of leafy greens which naturally contain folate. This is something I recommend universally in my own practice.

Methylated folate has been shown to be more effective than folic acid if a MTHFR polymorphism exists, and is at least as effective as folic acid in the general population (i.e. those without the polymorphism).

In terms of dosing, the minimum RDA for folic acid in pregnancy is 400-600mcg daily. In my own practice, I tend towards the upper dosing limit of 1000mcg per day of methylated folate, to ensure that women are getting the vitamin in the amount, and form, that their body needs most. 

I hope you have found this helpful, and do let me know if you have any questions!

If you are hungry for more evidence-based information in your pregnancy, sign up for my free webinar: 7 Pregnancy Myths Debunked – and get the information you need to have a healthy pregnancy and a thriving baby.

And if you are a care-provider looking for evidence-based resources for your pregnant patients, please get in touch with us at

In health,

Dr Jocelyn Land-Murphy, ND

Terra Life

Disclaimer: The information and content provided is for general educational and informational purposes only and is not professional medical advice, nor is it intended to be a substitute therefore. Please consult the Disclaimer and Terms of Use for full details.


Boris , M. et al. (2004). Association of MTHFR gene variants with autism. Journal of American Physicians and Surgeons, 9(4): 106-108.

De la Calle, M. et al. (2003). Homocysteine, folic acid and b-group vitamins in obstetrics and gynecology. European Journal of Obstetrics and Gynecology and Reproductive Biology, 107(2): 125-134.

Grandone, E. et al. (1997). Factor V Leiden, C > T MTHFR polymorphism and genetic susceptibility to preeclampsia. Thrombosis and Haemostasis, 

Nelen, W. et al. (2000). Hyperhomocysteinemia and recurrent early pregnancy loss: a meta-analysis. Fertility and Sterility, 74(6): 1196-1199.

Obeid, R. et al. (2013). Is 5-methyltetrahydrofolate an alternative to folic acid for the prevention of neural tube defects? Journal of Perinatal Medicine, 41(5): 469-483.

Prinz-Langenohl, R. et al. (2009). [6S]-5-methyltetrahydrofolate increases plasma folate more effectively than folic acid in women with the homozygous or wild-type 677C–>T polymorphism of methylenetetrahydrofolate reductase. British Journal of Pharmacology, 158(8): 2014-2021.

Venn, B. et al. (2003). Comparison of the effect of low-dose supplementation with L-5-methyltetrahydrofolate or folic acid on plasma homocysteine: a randomized placebo-controlled study. American Journal of Clinical Nutrition, 77(3): 658-62

Leave a Reply

Your email address will not be published. Required fields are marked *



8 Proven Shortcuts To A Healthy Pregnancy

it's free!
Protecting your personal information is of utmost importance to me