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  • Writer's pictureNancy Mullan, MD

Using Nutrition to Bypass an MTHFR Mutation

Updated: Jan 23, 2020

The MTHFR gene encodes for the MTHFR enzyme.

The MTHFR enzyme converts 5,10 methylene folate to 5 methyl folate, depicted at the 11:00 and the 6:00 positions respectively in cycle number 3 in the diagram below.

There are two MTHFR genes that impact this conversion: MTHFR C677T and MTHFR 03. A different MTHFR gene, MTHFR A1298C, works in another way that I described in a prior email, What About MTHFR A1298C? What Does That Do? I am going to leave that issue aside for now. If you want to learn more about MTHFR A1298C, click here to read the blog post.

When you have a mutation in either the MTHFR C677T or the MTHFR 03 gene, the enzyme produced by the gene works more slowly. An MTHFR 03 mutation generates an even more profound slowdown in enzyme activity than a mutation in MTHFR C677T. So, with either of these mutations, you produce less 5 methyl folate.

5 methyl folate is important because it is the methyl group at the 5 position on the folate molecule that goes on through a series of reactions to supply your body with the methyl groups that it needs. Your body needs methyl groups for proper immune function, for protection from chronic inflammation, for neurologic function, for histamine deactivation, for hormonal balance, and for neurotransmitter balance, to name just a few processes.

Methyl groups are genetic regulators. At any given time, 80% of your genetic material should be silent. Methyl groups silence genes. They prevent aberrant gene expression thereby protecting you from autoimmune disorder, a tremendously important function.

A double mutation in either of these MTHFR genes generates more issues than a single one as you might anticipate. How significant your health problems become overall depends upon what other mutations are present in the genes in your methyl group producing pathway, and what kind of environment you have been providing for them with what you are eating. 

Attention to diet is critically important if you have an MTHFR mutation, because your diet produces the material your genes are bathed in. Most MTHFR + people do well with some juicing or smoothies. What you put in them depends on you and what enhances your body's function. Lean away from starchy carbohydrates because they provide food for organisms in your GI tract that may give you symptoms. Your immune system may not be able to keep your gut environment optimal because the MTHFR mutation limits the methyl groups it needs to make immune components. You will not do well with junk food or food with poor nutritional value.

There are many vitamins and minerals that you need for the smooth function of your methyl group producing pathway. You need to be sure that you have them on board with biochemical testing. This testing costs money, but it does not all have to be done at once. You can learn clinical signs that tell you whether you are going in the right direction. This can hold the cost of testing down. No matter how well motivated you are, don't overspend on healing. Getting well with an MTHFR mutation may feel like overspending from the start, but manage what you are spending. Staying well goes on over time. At no point should you be overspending on this process.

Besides optimizing the conditions in your body for making methyl groups, you can supplement 5 methyl folate and other methyl donors. You may have a nearly unlimited need for methyl group supplementation or you may be on a methyl budget. Other mutations in your methyl group producing pathway may limit your tolerance for methyl groups. Knowing your genetics for this whole pathway, not just the MTHFR genes, will help you to determine how to supplement correctly to get the pathway running smoothly. Pounding it with heavy doses of 5 methyl folate or other methyl donors like methyl B12 may not be such a red hot idea for you....

The supplementation of 5 methyl folate and other methyl donors is easy for some people. They take them and they feel better. Some feel decidedly worse. This can happen for a number of reasons. You may have exceeded the limit for methyl groups in your body or taken too much too soon. Alternately, you may have activated some long defunct biochemistry and entered a period of adjustment. You may be experiencing the effects of overdue toxic metal excretion, or enhanced immune activity may be killing off some non optimal organisms in your body. You may not have enough B12 on board. There is a universe of biochemistry in your body and the reasons why you react to supplementing methyl groups can be myriad.

My hope is to give you the opportunity to get your body functioning, the opportunity to learn the detail of what you need to know to feel well. I am an MTHFR specialist with over ten years of experience with this gene and its consequences. I treat more MTHFR positive patients than any other doctor in the US. Don't stumble around in the dark. You can dig yourself into a hole trying the wrong solutions. Your doctor may have familiarity with MTHFR, but he may not know enough genetics to treat you if yours are tricky or if you have been sick for a long time. You end up feeling lost and desperate and as if there is no hope. I help people just like you.

I have a free, downloadable ebook at that gives you further detail about these issues. Click here to download.

If you have never worked with me before, try an Exploratory Conversation. In this 30 minute discussion, I will listen to your symptoms, look at the lab tests you email me, tell you what I think, and leave you feeling enlightened and relieved. What I tell you will make sense. You will feel that there is a path forward, that you have found a clinician who 'gets it.' 

My fee is $129 for this conversation. It is quick and easy and does not involve becoming a patient. I can clarify your confusion and pull you out of the muddle.

I look forward to being able to help, Dr. Nancy

What people like you are saying about Dr. Mullan’s work:

I shudder at the thought of what my family would be like without Dr. Mullan. Thankfully, with her help, we have stopped my husband's chronic 30 year battle with kidney stones. He is no longer forming them and is stone free. My thyroid is now working normally, my body temperature is almost normal and my hair has grown back. My oldest daughter's Autism is in the process of being reversed and her hair pulling has stopped. The greatest blessing from our good health is the birth of my second daughter Ava, now one-year-old. At 50 years old I carried her to term. One of my doctors commented to me saying “ you are carrying this baby like a 22-year-old.” Yes, I am because of Dr. Mullan and working on my methylation pathway. One by one she is knocking off symptoms and bringing us back to health. The future is bright! Thank you, Dr. Mullan, for the work you do.


Wow. I feel great. Thank you for your help. It's amazing really. Like a light turned on. Curious to see what the next tests show. To ride this peak indefinitely is my goal. Ha. I have energy again. Yay!

Really grateful,


I am so relieved. My daughter is doing SO WELL since we started with you! We have been to so many doctors and tried so many things.Now I can start working on my own program with you....


So excellent! I literally learn something every single time and I get clarification on things that have been lingering in my mind… VB

You are giving people a huge gift by empowering them… It’s about helping the patient become their own healer by taking them to a higher level of consciousness… AL

Thank you so much, Dr. Mullan. Thank you so, so much for everything you do. MS

Wow! I have to tell you, this was such an uplifting session. It’s so nice to hear good news, especially about a child. Anxiety, OCD and a host of other mental/psychiatric symptoms have been a huge hurdle for me. So to hear this story of all those awful symptoms totally going away is such a bright light for me!!!! TR

Fantastic, caring, smart, savvy doc. I worked with Dr. Mullan for a couple of years to help MTHFR mutations and their associating expressions! To say the least! She's brilliant. At that time she had weekly calls for her patients - free - where we could ask questions and she would reply. What doctors do this? She does. She's also an animal lover and is right on about the way she practices medicine. I highly recommend her. In good health!


"Dr. Nancy Mullan is a beautiful person. She is an expert in her field and has helped our family so much. I am very grateful to her. She came highly recommended and I know why. I would recommend her and her website for information re: healing from a genetic point of view. Thank you, Dr. Mullan, for everything.”


"Dr.Mullan has helped me with issues that I have struggled with for years. She is knowledgable and practical. I would recommend her to others.”


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