Your immune system is made up of white blood cells (WBCs).  WBCs are responsible for identifying foreign organisms, including bacteria and viruses, and eradicating them.  For your immune system to be effective there must be an adequate number of WBCs circulating in your bloodstream.  When laboratories examine your blood, they count your WBCs. If your WBC count is low or borderline low, this may explain why you catch colds so frequently.  The reason for a chronically low WBC count could be a genetic issue.

Genes Determine How You Process Vitamins

Genes play a role in how efficiently your body processes certain vitamins that are necessary for WBC production.  The main vitamins involved are folate, vitamin B12, and to a lesser extent, niacin.  There are variations of the genes that are responsible for processing these vitamins.  Depending on which variants you have will play a major role in your WBC production.  Some genetic variations are much less efficient at processing vitamins than others.  The good news is that you can compensate for any variation through diet and supplementation.  

Genetics Determine Your Nutritional Needs

The genes discussed in this article contain the codes / blueprints to make enzymes.  Enzymes are proteins that speed up processes in the body.  The efficiency of an enzyme depends on the blueprint used to make it.  The less efficient your enzymes, the more dietary nutrients you require to complete processes.

Certain Vitamins Are Needed to Make White Blood Cells

Your body needs folate and Vitamin B12 to make both WBCs and red blood cells (RBCs).  Your liver must convert folate into its most active form, 5-Methyltetrahydrofolate (5-MTHF), so that your body can utilize it.  It does this by using an enzyme called 5-Methylenetetrahydrofolate Reductase (5-MTHFR).  You have a gene in your DNA that contains the blueprint to make 5-MTHFR.  That gene varies from person to person.  It is known as the 5-MTHFR 677 gene.  Your blueprint for making 5-MTHF depends on which gene variation you express as described below.  

There are three normal / common variants of the gene 5-MTHFR “677”:    

  1. MTHFR C677C- This is the most common form.  It is also the most efficient at making 5-MTHF  
  2. MTHFR C677T- This is the second most common form.  40% of the population has this variant.  The blueprint from this gene results in a 40% decrease in ability to make 5-MTHF compared to the C677C variant.
  3. MTHFR T677T- is found in 8-12% of the population.  It is associated with a 70% decrease in ability to make 5-methyltetrahydrofolate.

Different Genetic Variants Mean Different Nutritional Requirements

People with the second and third genetic variants listed above will require more dietary methylated folate than those with the first variation.  If they do not meet this need, then their WBC count may be low, and they may also show signs of anemia.  The more dietary 5-MTHF a person consumes, the less they depend on the enzyme needed to make 5-MTHF.  Great sources of 5-MTHF include spinach, romaine lettuce, cauliflower, asparagus, broccoli, kale, cabbage, strawberries, oranges, grapefruit, fermented foods such as kefir, water kefir, kombucha, sourdough bread, brewer’s yeast, and bell peppers.  You can also purchase 5-MTHF supplements.

There are other genes to consider as well.  I will not go into detail about these, because I feel that the MTHFR “677” genetic variant example above adequately demonstrates how genes play a role in our nutritional needs.

The DHFR Gene and Folate

The DHFR gene codes for the Dihydrofolate reductase (DHFR) enzyme, which is involved in making 5-MTHF.  DHFR converts dihydrofolate into tetrahydrofolate.  The liver needs niacin and niacinamide for this process.  There are genetic variants that code for DHFR, just like there are variants for the MTHFR enzyme.  Some are more efficient than others.  Individuals who have a less efficient variant of DHFR may need to compensate with  extra niacin and niacinamide in their diets.  Great sources include beef liver, chicken breast, tuna, salmon, ground beef, avocados, brown rice, whole wheat, mushrooms, green peas, and white potatoes.

Homocysteine Metabolism Can Increase Your Folate and Vitamin B12 Needs

Your body’s ability to metabolize homocysteine into methionine also plays a role in determining how much folate and vitamin B12 you need to intake daily.  Homocysteine is a protein that can cause cardiovascular issues, by inflaming and damaging blood vessels. Methionine is an amino acid and an important detoxification compound in the liver. It helps detoxify heavy metals and certain medications.  

The genes 5-methyltetrahydrofolate-homocysteine methyltransferase reductase (MTRR) and 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR) code for the enzymes, methionine synthase reductase and methionine synthase, respectively.  These enzymes are needed to convert harmful homocysteine into safe methionine.  These enzymes require folate and vitamin B12 to do this.  

Depending on the genetic variants of MTR and MTRR you possess, determines how efficiently this process takes place.  The less efficient the variation, the more vitamin B12 and folate you will need for this process, which means less folate and B12 for making WBCs.  If you do not have enough vitamin B12 and folate, then homocysteine can accumulate and increase your risk of developing cardiovascular disease.  Also, your liver’s detoxification processes will be impaired.

Summary of Vitamin Food Sources

Vitamin B12 sources- Beef Liver, Beef Kidney, Clams, Sardines, Beef steak, Tuna, Trout, Salmon, Dairy, Eggs.  When purchasing a vitamin B12 supplement make sure that it is in the methylcobalamin form

5-MTHF sources- Spinach, Romaine Lettuce, Cauliflower, Asparagus, Broccoli, Kale, Cabbage, Strawberries, Oranges, grapefruit, Fermented foods such as kefir, water kefir, kombucha, sourdough bread, Brewer’s yeast, and Bell peppers.  When purchasing a folate supplement make sure that it is in the 5-MTHF form

Niacin sources- Beef Liver, Chicken Breast, Tuna, Salmon, Ground Beef, Avocados, Brown Rice, Whole Wheat, Mushrooms, Green Peas, White Potatoes

Recommended Supplements

B12 Folate 60's

B12 Folate

A great source of

5-MTHF and Methycobalamin

Which are the forms necessary for

those who have genetic variants

resulting in a decreased ability to

make 5-MTHF and Methylcobolamine.

Liver Beef 1000 mg 125 caps















Liver Beef 

is a great source of

niacin and Vitamin B12,

and many other vitamins

and minerals

Niatab 500 100 T

Niatab 500

By Douglas Laboratories is a

sustained release form of niacin,

which allows you to get all the

benefits without the flushing.  

Niacin is necessary to convert

Folate to tetrahydrofolate.  

Want to Get Your Immune System Evaluated?

At our Manhattan office, we first order a blood exam (CBC with differentials) to see if your white blood cell count is low.  If it is low, we make dietary and supplement recommendations.  We then retest your blood after two months.  Upon retesting, if it is has not increased, then we order a buccal (cheek) swab to test for genetic variants.  We do kinesiology testing and treatments to determine which nutrients you need to correct the problem.  Please call us at 212-286-2012 if you are interested.


MTHFR. Genetics Home Reference (GHR).  November 2014.

Varga EA, Sturm AC, Misita CP & Moll S. Homocysteine and MTHFR Mutations: Relation to Thrombosis and Coronary Artery Disease. Circulation. 2005; 111:e289-e293.

Carmel R, Green R, Rosenblatt DS, Watkins D. Update on cobalamin, folate, and homocysteine. Hematology Am Soc Hematol Educ Program. 2003:62-81. Review.  Citation on PubMed

Doolin MT, Barbaux S, McDonnell M, Hoess K, Whitehead AS, Mitchell LE. Maternal genetic effects, exerted by genes involved in homocysteine remethylation, influence the risk of spina bifida. Am J Hum Genet. 2002 Nov;71(5):1222-6. Epub 2002 Oct 9.  Citation on PubMed or Free article on PubMed Central

Bosco P, Guéant-Rodriguez RM, Anello G, Barone C, Namour F, Caraci F, Romano A, Romano C, Guéant JL. Methionine synthase (MTR) 2756 (A --> G) polymorphism, double heterozygosity methionine synthase 2756 AG/methionine synthase reductase (MTRR) 66 AG, and elevated homocysteinemia are three risk factors for having a child with Down syndrome. Am J Med Genet A. 2003 Sep 1;121A(3):219-24.  Citation on PubMed


May 24, 2020