Folic Acid: Friend Or Foe? How The MTHFR Genetic Variation Can Affect Your Fertility & Pregnancy

Folic Acid: friend or foe? How MTHFR genetic code can affect your health.

Most women already know that folate (vitamin B9) is an important vitamin for expectant mothers and is taken to prevent the development of spina bifida and other birth defects such as cleft palate and even tongue-tie. Not having enough of the right type of folate in one’s system can also be one of the causes of multiple miscarriages and other problems with fertility. It can also be important to support maternal mental health and prevent post-natal depression.

What is less well-known, is that many people inherit a genetic SNP called Methylenetetrahydrofolate Reductase (commonly known as MTHFR) which can alter the way we metabolise certain forms of folate especially synthetic manmade folic acid. Being aware of the presence of MTHFR and which type of folate to prioritise, can help with fertility chances as well as producing a healthy baby and maintaining resilience as a new mum during the fourth trimester.


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You would have thought that eating folic acid fortified bread and cereals and even supplementing with a multivitamin or B complex containing folic acid is the simple solution. However up to 70% of us struggle to convert the synthetic manmade folic acid used in these vitamins and foods into a form that the body can use.

This unconverted folic acid can build up in the blood showing elevated serum folate levels and can become toxic to our system. At the same time this leaves the cells and processes that need the folate most, starved of this essential vitamin. If this poor conversion occurs over a long period of time, then health can start to deteriorate and that is when certain fertility or problems with the baby can start to develop.

So why can’t 60-70% of the population convert synthetic folic acid into useable folate? It is probably due to this common genetic code called MTHFR. Mutations or errors in genetic sequences of MTHFR alter DNA function and if activated (switched on) the cellular damage caused is believed to be one of the key drivers in the exponential growth in cancers, autoimmune conditions, autism, ADHD, depression, schizophrenia and other mental health conditions. It may well be part of the picture of progression of neurological diseases such as Multiple Sclerosis, Motor Neurone Disease, Parkinson and Dementia.

There is no need to panic, carrying MTFR genetics is not an automatic flag that you will go on to develop any of these debilitating health conditions. Far from it. Knowledge is power, and by understanding the role MTHFR plays it can enable you to take control of your health through easy adaptations to your lifestyle and diet can make all the difference.

What is MTHFR?
The MTHFR gene sits on Chromosome 1 and provides instructions to the body for making methylenetetrahydrofolate reductase, an important enzyme that processes the natural nutrient folate into a form the body can use. In addition, when MTHFR genes work properly they support important cellular activity and the creation of proteins, antioxidants, detoxification of toxins, hormone metabolism, balanced brain chemistry, the ability to turn neurotransmitters on and off, and the process of managing inflammation within the body, tissue repair, energy and mitochondrial support, and reduce the aging process.

However, if you have one or more activated MTHFR genes your body can’t break down synthetic folic acid which can create high homocysteine levels. This in turn increases inflammation in the body and the risk of health issues and disease(s) such as heart attack, stroke, venous thrombosis, birth defects, migraine, recurrent early miscarriage, osteoporosis, thyroid conditions and cancer.

Without this crucial folate mechanism working optimally, the body cannot synthesise the essential antioxidant, glutathione, which can lead to further damage of fundamental brain neurotransmitters and may be the start of or speed up the progress of neurological disorders and chronic disease.

It is possible to test for MTHFR genes (of which there are over 50 variations) through a simple saliva DNA test. Researchers have identified C677T and A1298C (often written as 677 and 1298) as the most common genetic single nucleotide polymorphisms (frequently called SNPs) and are more likely to affect folate metabolism.  You can also ask your practitioner to organise a methylation panel which is a blood test to check to see whether the folate is being metabolised efficiently. Homocysteine testing (which is another blood test) can also identify if there is a current high need for vitamin B6, B12 and folate.

If tests are positive for an MTHFR mutation then the most important thing to remember is the mutation might not have been expressed (switched itself on). This may be because you are living a healthy stress-free life already and eating lots of leafy green vegetables. It may also be that you have other genetic strengths to balance this SNP.  If folate related health conditions/symptoms are apparent, then it might be possible to ameliorate these at the root cause and manage them more positively.  Simple diet and lifestyle changes and in some cases specific supplementation can safeguard against future health issues or deterioration.

Our twenty top tips to be well with MTHFR

This checklist of simple lifestyle tweaks can be game changers when it comes to minimising the likelihood of MTHFR SNPs impacting on your health and wellbeing. Keep them to hand and do your best to adapt your lifestyle to supporting your genetic profile:

  1. Enhance your diet with foods naturally rich in folate. Enjoy foods such as almonds, avocado, banana, broccoli, romaine lettuce, kale, spinach, asparagus, swiss chard and other leafy greens that contain natural sources of folate. Ideally, these would be raw such as in kale salad, kale chips or blended into green smoothies. You can also cook the green vegetables lightly in olive oil and garlic with Himalayan salt.
  2. Ensure you avoid synthetic folic acid supplements (this is the folic acid in most multivitamins and B complex supplements) or any food fortified with folic acid (many cereals, breads and vitamin-enriched drinks).
  3. Many people with MTHFR will need a supplement with natural folate (look for methyltetrahydrofolate, calcium l-folinate or food-grown folate). If pregnant, it is important to find a pregnancy multivitamin containing these natural forms of folate and not folic acid.
  4. Consider taking folate supplements if you are taking folate-blocking medicines such as the contraceptive pill. If you are on Methotrexate for conditions such as rheumatoid arthritis then ask for a methylated form of folate for your weekly folate support.
  5. Be aware of any drugs which can increase homocysteine such as nitrous oxide (most used in dentistry) and antacids as they block absorption of vitamin B12 and other nutrients.
  6. Consider a methylation panel and/or a homocysteine test.
  7. If you are pregnant or planning pregnancy find a practitioner who is knowledgeable about MTHFR to guide you throughout your pregnancy and until your baby is at least one year old.
  8. Aim to eat a gluten-free diet. Wheat (especially flour which is fortified with folic acid) should be avoided and slow up on oats, rye and barley. You don’t have to be as strict as those with coeliac disease with avoiding gluten, but do try to keep it down.
  9. Cut down on cow’s dairy. Some people better tolerate goat, sheep and buffalo dairy products instead.
  10. Increase your intake of whole foods and home-prepared meals.
  11. Eat at least 10 different fruits and vegetables daily and aim to eat the rainbow of colours from your food.
  12. Juice or blend fruits and vegetables regularly to make fresh juices and smoothies.
  13. Keep intake of processed foods to a minimum.
  14. Eat grass-fed meat and free-range or organic high-welfare poultry and eggs.
  15. Eat smaller, but more frequent meals throughout the day, always with some form of protein, for more continuous blood sugar levels.
  16. Be extra careful about toxins, which you may have more trouble processing than some people. This can mean reducing exposure to plastics in food production/storage, and eating less of foods known to contain toxins, such as fish with high mercury content, and rice which might have high arsenic content.
  17. Invest in a water filter, and always drink plenty of filtered water. Even better, also filter the chlorine out of your shower and bath water.
  18. Get hot and sweaty at least once per week (ideally three times per week). This could be through exercise, yoga, sauna or Epsom salt baths.
  19. Get lots of sunshine and fresh air on a daily basis.
  20. Find ways of reducing stress in your life. Chronic stress can often be the tipping point that activates our genetic mutations and may also exacerbate existing health conditions. Find de-stressing activities that work for you such as yoga, mindfulness, walking, etc.

A word on vitamin B12
People with MTHFR SNPs can also become deficient in vitamin B12, which your body needs to process folate properly. Vitamin B12 is crucial for you and your baby’s brain, nervous system and also your red and white blood cell formation. Therefore, it is important to ensure your diet is rich in natural sources of B12 such as beef (grass-fed), feta cheese, fish, liver, and sardines.

Some women who are looking to optimise their fertility and pregnancy also benefit from vitamin B12 supplementation given alongside the folate support and again your NatureDoc practitioner can identify if a deficiency is present.

Supplementing folate on its own can mask a B12 deficiency and this is why it is important to test at the outset and to retest from time to time. Again, in most cases a methylated form of B12 such as methyl cobalamin (methyl B12) would be more helpful than cyanocobalamin which is the form used in most standard vitamin supplements. By supplementing with active forms of theses crucial vitamins, we may be able to bypass metabolic glitches and support optimal B12 and folate requirements.

So, as you can see, MTHFR SNP’s can play a significant role in the development of fertility and pregnancy related health concerns as well as the formation of a healthy baby and maternal mental health. However, more importantly with some tests and knowledge we can address the possible root causes of these problems, and better still have a positive strategy to help prevent such negative outcomes.

MTHFR mutations affects most of us directly or indirectly, so please share this post and let this knowledge empower good health and happy healthy mums and babies!


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    1. Hi Kate. I have not found a non-plastic water filter jug but as far as I am aware they are all BPA free. We have an under sink water filter installed, which we find the best solution as it is stainless steel and you can choose level of filter you need. I hope this helps.

  1. Great information here, particularly love your list of foods with high concentrations of naturally occurring folate. Chickpeas are another great way to bring extra natural folate into your diet – so a good homemake hummus with kale is a great way to go!

    1. Hi Lucinda,

      I am currently on 5mg of folic acid, I have been diagnosed with the MTHFR gene (MTHFRc.665C>T variant & MTHFRc.1286A>C variant) and am trying to conceive. Should I be taking the food grown folic acid? There doesn’t seem to be one which is at the higher dose I need. Should I also be taking the B vitamin supplement? I haven’t been told about this as my doctor only tested me for it and was not specialised in this specific field. It’s been quite difficult to find anyone who can direct me in how to move forward with this!

      Many thanks

      1. Hi Fleur, Good to hear from you. If this is a medically prescribed folic acid it may well be Leucovorin which is folinic acid and is in the bioavailable form. If it is not calcium folinate, folinic acid or methyltetrahydrofolic acid then do book in to see one of my team to discuss and we can find the right supplement to take and adivse you how to optimise your fertility with this in mind.

  2. hi there, I know from testing in Australia that I have a double genetic mutation of MTHFR. My 13 year old is now displaying symptoms, ulcers, tiredness, large RBC size etc. Is there someone I could talk with who is very familiar with this genetic problem in particular dosing with children and testing for children. Thank you

    1. We do look after some Australia based families and we would be more than happy to help – please be in touch with our reception team. Best wishes Lucinda