What you need to know about MTHFR and PCOS

MTHFR? What on earth is that? MTHFR is one of the most important enzymes that the body creates and is needed in a number of bodily functions. A deficiency in the all-important MTHFR enzyme has been associated with (1):

  • stroke
  • venous thrombosis
  • increased risk of heart attack
  • several types of cancer
  • congenital defects
  • inflammatory bowel disease
  • several neuropsychiatric conditions.

Now, I know that sounds pretty scary and you may be wondering what on earth this has to do with you.

Well, roughly 30-50% of the general population have a mutation in the gene that is responsible for producing the MTHFR enzyme. That is a huge portion of the population and the impact is often significant (2).


You see, MTHFR is responsible for a number of things, including (3):

  • detoxification
  • producing energy
  • repairing and building DNA and RNA
  • building immune cells
  • repairing cell membranes
  • processing hormones

So, for your body to function as it should, for your hormones to be processed and managed, for your ovaries to produce eggs, you need to have MTHFR. Without it, you will constantly be fighting your body and your PCOS symptoms.

So, now that we know what MTHFR is and why it is so important, let’s have a look at what you need to know about MTFHR and PCOS.

What is MTHFR gene mutation?

Well, we’ve already said that it is a gene mutation, something that we are born with. It can get very complicated in how the gene works but you need to understand the basics so bear with me.

The MTHFR gene is responsible for producing an enzyme that makes folic acid usable by the body. It does this through a process called methylation, which you can see below (4).

mthfr-pcos-folic-acid-metabolismIt is a complex process but you can see in that very last step that MTFHR is needed. Without MTHFR, you will really struggle to use folic acid, with a lot of health consequences.

What do we need folic acid for?

Well, the short answer is that we don’t necessarily need folic acid. What we do need is folate. Folate is one of the Vitamin B’s and it is important for our health and general function. A folate deficiency is often seen in (5):

  • Poor immune function; frequently getting sick
  • Chronic low energy (including chronic fatigue syndrome)
  • Poor digestion; issues like constipation, bloating and IBS
  • Developmental problems during pregnancy and infancy, including stunted growth
  • Anemia
  • Canker sores in the mouth and a tender, swollen tongue
  • Changes in mood, including irritability
  • Premature hair graying

Folate is also essential for the development of the nervous system in developing foetuses. That is why many of our foods are now fortified with folic acid and women who are trying to conceive are encouraged to take folic acid supplements.

Folate vs Folic Acid

This is important to understand. The main difference between folate and folic acid is that folate is readily used by the body. It doesn’t need the MTHFR enzyme to be absorbed by the body and put to use. Remember the diagram from earlier? If we are taking folic acid supplements and we have the MTFHR gene mutation, we won’t be able to put that folic acid to use.

But it gets even worse. If we do have the MTHFR gene mutation, our bodies will struggle to deal with the folic acid and the folic acid will remain in our bodies and blood stream where it can actually become toxic (high levels of folic acid have been linked to cancer).

So, it’s important that we make sure that we are giving our bodies the right supplements, not only to avoid the potentially toxic effects of folic acid, but also to make sure that our hormones are well managed, our PCOS symptoms under control.

MTHFR testing

To be honest, testing is not often carried out in the UK and it can be done privately in the US. A blood sample is drawn and sent off to the lab for testing. If you are interested in having a test done, 23andme.com are able to carry out the test.

Now, whether or not you decide to undergo testing, it would make sense to ensure that you are getting sufficient quantities of folate, in a form that your body can use, to ensure that you don’t struggle with any kind of folate deficiency.

So, let’s talk more about folate and where you can get it from.

Dietary Sources of Folate

Folate is readily available in a lot of fresh, whole foods. Here are the tops sources of dietary folate, according to Dr Josh Axe:

1. Spinach — 1 cup cooked: 262 mcg (66 percent DV)

2. Beef Liver — 3 oz: 215 mcg (54 percent DV)

3. Black Eyed Peas — 1 cup cooked: 210 mcg (52 percent DV)

4. Asparagus — 8 spears: 178 mcg (44 percent DV)

5. Broccoli — 1 cup cooked: 104 mcg (26 percent DV)

6. Brussel Sprouts— 1 cup cooked: 156 mcg (40 percent DV)

7. Mustard Greens— 1 cup cooked: 104 mcg (26 percent DV)

8. Kidney Beans — 92 mcg (24 percent DV)

9. Romaine Lettuce — 1 cup raw: 64 mg (16 percent DV)

10. Avocado — ½ cup: 59 mcg (15 percent DV)

11. Wheat Germ — 2 tablespoons: 40 mcg (10 percent DV)

12. Orange — 1 medium: 29 mcg (7 percent)

So you can see that by eating a well varied diet, you are likely to be able to get your daily recommended allowance of folate.

Metformin and Folate

MTFHR-and-PCOS-greensNow, this is really important, especially for women with PCOS as Metformin has become one of the most prescribed medications for treating PCOS. Metformin has been shown to impact on the absorption of Vitamin B12 and folate, often leading to deficiencies in both of these important vitamins (6).

So, if you are taking Metformin, please do consider the dietary guidelines above, and possibly speak with your doctor about folate supplementation (remember, you want to steer clear of folic acid so make sure you ask for L-Methylfolate)

Okay, so let’s summarize:

  • MTHFR gene mutation affects 30-50% of the general population
  • It often results in a folate deficiency which can really make our PCOS symptoms worse
  • We should be focusing on folate instead of folic acid
  • We can source folate through our diet by ensurIng that we eat a variety of leafy greens.
  • If we are going to supplement, we need to look out for L-Methylfolate

If you have any experience of living with an MTHFR gene mutation, I’d love to hear from you! Leave me a comment below!

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Tarryn Poulton

Tarryn Poulton

Tarryn Poulton is a PN1 Certified Nutrition Coach and PCOS expert who has been a leader in the online PCOS space for over 8 years. Tarryn has the support of leading clinicians from around the world who support her scientific approach to understanding and talking about PCOS this includes all medical journals and ongoing research. You can read more about Tarryn and the team here.

23 Responses

23 Responses

  1. How much folate we need to receive per day? And if we receive it more than we need, will it have side-effects for us?

  2. For PCOS you should see a Reproductive Endocrinologist.
    Here in the US, Labcorp does the gene mutation lab test, most insurance won’t cover it, but it’s not terrible expensive, around $400 I think.

    I was diagnosed w/ PCOS at the age of 30, this was after 12 years and I don’t even know how many doctors ( family practce, ob/gyn, internal med) I am thinking it is around 15-18 doctors, who told me 1 or more of a version of the following 3 things… 1. Lose weight, you are to fat – preaching fewer calories in+ more calories out = weight loss… WRONG. 2. Go on the pill…. My grandmother died of a brain aneurysm at age 42 and 8 months pregnant ( which I always included in my medical history)……no way, the pill terrified me. 3. Seek Psychiatric care, you are a hypochondriac and prob need medication help.

    So at age 30 after joining a gym, eating 1200 cals or less each day, I found that after 9 months not only was I not loosing, I was gaining, and not muscle. So I went to a new ob/gyn who diagnosed PCOS, because she had it and my symptoms were like hers. After talking w/ some women Iknow, one recommended I see her Reproductive Endo…..she is great. She believes my pcos has been with me since the onset of puberty. I always had late, lean, very infrequent periods and cystic acne, along w/ other health issues.

    So at 36 I got married and a year later we tried, w/ drug assistance, to have a baby. All in all I had 18 chemical pregnancies, a nd a DNC @9 weeks. After this was when we found out That I have the mthfr, 1 jacked up copy of each of the 2major genes that are looked at. We are lucky, we were able to conceive and carry to term. We now have our beautiful boy.

    What I found out is that in my generation of my mom’,mom’s family approx 1/3 of us girls have both PCOS and MTHFR. I would love to get us hooked up w/a researcher.

  3. I am 63 years old. Luckily I gave birth to 2 daughters with no problems as I have been diagnosed with the MTHFR 2 gene mutation 7 years ago. However, my oldest daughter had a miscarriage with her first child due to the MTHFR 1 gene mutation. That’s what lead all of us to be tested. I suffer from depression and fatigue. I am also obese. Yesterday, after having blood tests and urine testing, my doctor is prescribing Metformin and Trulicity to help with my health issues. Also informed me to stop taking B12 vitamins as my levels were very high. She also suggested to start taking Contrave to help aid with my weight loss and depression. ( I currently am taking Dueloxitine for depression). In your opinion, are there any red flags coming to mind? The only other drugs I take are Plavix and Metroprolol (heart palp.) any info you have is greatly appreciated.

  4. OMG!!! I had no idea that MTHFR and PCOS were linked together. I just thought that it was a coincidence that I had both. I was first diagnosed with PCOS at 17. After being put on birth control immediately after my diagnosis I had a DVT and PE a couple of months later. Due to my family history of those, they found that I had the gene mutation but NO one mentioned/has even mentioned now that they were connected; we all thought it was just a weird connection to explain my young age and close family history of it (my father has had 2 in the past). Since then I have been taking 1mg of folic acid per that doctor’s (a pediatric hematologist) orders for almost 10 years now. SO to read now that taking this drug is toxic is very unsettling to hear about. Who do I see now that I have this news? My general doctor or a new hematologist?

  5. I was just recently diagnosed with PCOS in February. For the last few years, anytime I get blood work done it says I have a critically high folate level. I always asked my Dr. why this was and they always dismissed me. This article has helped me understand that my body isn’t using the folate as it should and it’s building up in my system. I will definitely be mentioning this to my Dr. next time I go in. Thanks for the great information!

  6. Ive had PCOS for about 23 years and in the last couple years I found out I have the MTHFR gene. My Dr has advised I take fola pro which is made by Metagenics. You can get this thru Amazon and some nutrition places have it as well. $40 per bottle. This has done amazing things for so many parts of my life, I do take metformin B vitamins as well. My Dr is the one who prescribed the blood test to check on it so ladies ask your doctor. Once that folate starts working your depression symptoms will lessen you will just feel better overall and you will heal cashier if you are injured because your cells regenerating faster.

  7. I found out I have MTHFR 2 years ago when my daughter was stillborn. I have also now been formally diagnosed with PCOS.

    1. I am so sorry to hear about your daughter, Amy. I had a very difficult birth with my daughter and she had to be resuscitated. It’s very scary and very traumatic!

  8. I contacted 23andme.com and it doesn’t look like they do a MTHFR analysis (although they do a genetic health risk panel)… Do you know of any other places that test for it?

    1. You can upload your 23andme raw data to dr. Rhonda Patrick’s nutrigenomics service and get a report on several genes including MTHFR. I just did it and it’s the best $10 I’ve ever spent. It’s at http://www.foundmyfitness.com
      She’s a wealth of information too.

    2. I got my MTHFR analysis through my psychologist’s office. It was part of a gene test to see which medicines would work best for me. It usually costs $6,000, but you pay according to your income. Since I made less than $40,000 a year, I only had to pay $20, but this was in the US.

  9. Ladies,

    Just something to make mention of is there are certain things like Alcohol, tea and coffee that will strip folate away in a heartbeat (google folate muggers) and also if you have gut problems get them fixed ASAP because one of the biggest folate destroyers is what candida creates as waste acetaldehyde is a byproduct also of alcohol intake. If your gut is bad and you are overloaded with yeast constantly pumping this garbage out in your system it will take you ages to get better. A good way of fixing your stomach and digestion is getting a probiotic like symprove or dr ohhiras probiotics and drink clay there is also a product by cytoplan called methyl factors. If you cannot get this you can look at the ingredients and get those vitamins separately the more potent the better but must be the same because these types of B vitamins don’t need to be broken down by the body to be methylated they are already how they need to be to be absorbed. A good multivitamin that is food based is a must something like Naturelo multivitamins for women I have found to be beneficial to my wife. French green clay for fixing the gut and body is great (must be ultra ventilated) and find a french green clay drink protocol. Dr Hull wrote a piece on the benefits and how it pulls toxins and radiation from the body. Its cheap you can use it externally as masks etc paint yourself with it drink it and it gets rid of the garbage but then also gives you a lot of minerals etc and makes your skin feel and look amazing.

    I have researched and researched and put this information together over the years and have been helping my wife with this, and her improvements have been totally amazing. Treat your health to this and your body will thank you for it.

    I wish you all well in your endeavours.

  10. I have both the MTHRFR gene mutation and PCOS. My Dr. Prescribed me with Metformin but it makes my stomach feel nauseous, so I stopped taking it and got terrible headaches during the week.
    I decided to just take it when I know I’ll eat more sugar than I normally do but I’m not sure if the headaches are related…

  11. I am 33 and I have PCOS for 11 years. 1 year ago after misscariage, my doctor sent me to do the tests for trombophyllia and I have discovered MTHFR mutation. In the next pregnancy, I was taking prenatal suplements with 5-MTHF and metformin. Now, while breastfeeding I’m gaining too much weight so that’s why I’m on this site, searching for ideas for healthy diet which is a big issue for me because it seems that I cannot digest anything anymore except some cookies. I can’t eat anymore healthy vegetables like beans, cabbage or other which make bloating. My sense of bloating is more painful than a labour contractions. I hope I will find here more answers. In my country doctors dont know much about this mutation

  12. Just an update. 23andme.com no longer offers this type of testing for MTHFR gene mutation according to their customer support. Any other suggestions of where else to get tested?

    1. I have had 3 healthy children yet have also had 3 early miscarriages and one 19 week loss. Could I have the mutation even though I have had healthy children?

  13. I have an mthfr mutation! I love reading your stuff it’s much easier to understand!!! I have 6 our if the 8 symptoms you discussed above. However I would like to hear things about mthfr and pregnancy if you could indulge in that.

  14. I have the MTHFR gene mutation and PCOS. I didn’t know this when I was pregnant with my first child, and I was taking folic acid supplements left, right and centre the whole time. I was diagnosed with preeclampsia and my son was only 2.1kg at birth. I’m now pregnant again, and I’ve been taking folate (but not folic acid) supplements and generally trying to avoid foods that are toxic for people with this gene mutation. I’m now 36 weeks pregnant and my baby and I are perfectly healthy with no sign of preeclampsia or low birth weight at all. I know I can’t prove that the folic acid had anything to do with it, but my naturopath said that the fact that I’m not taking supplements that are actually toxic for my body this time around has probably played a role.

  15. I have the MTHFR mutation and I have done a lot of reading about it. This is one of the easiest to understand descriptions that I’ve read. While I don’t have PCOS, my daughter does. Unfortunately, we are struggling to find health care providers to help us deal with the effects. I have digestive issues and fatigue and most health care providers completely dismiss those symptoms. I look forward to reading more of your articles to help me navigate this problem!

    1. i have the MTRFR gene mutation and I ffinally got a RX for Deplin. I am also now on metformin as of last month. hoping to shed some of this weight and fix my fatigue. You can buy L-Methelfolate at whole foods just in a much lower dose than RX. and I should also mention no insurance in the USA will pay for Deplin. Mine is $179 every 90 days. but I have for sure seen a difference in my depression / fatigue.

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