Know Your Genes: FUT2 “Vitamin B12 Gene”

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23andMe, Ancestry DNA, FTDNA and several others


The FucosylTransferase 2 (FUT2) gene is associated with the synthesis of fucosyl transferase 2, an enzyme found to attach the bacterium Helicobacter pylori to the gastric mucosa, which affects the absorption of vitamin B12 in the gut. People with the A variant of the gene have been shown to be associated with an increased secretion of FUT2 enzyme which increases the susceptibility of attachment of the Helicobacter pylori.  

Vitamin B12 is also called cobalamin, and is absorbed from dietary sources or is synthesized by gut microbes. Vitamin B12 is necessary for the synthesis of red blood cells, myelin nerve sheath maintenance and in the synthesis of DNA.

Deficiency of vitamin B12 is associated with

  1. coronary artery disease (CAD)  in the Indian population
  2. Hyperhomocysteinemia, which is an elevated level of homocysteine and an independent risk factor for cardiovascular diseases.Hyperhomocysteinemia,  has also been found to be associated with Alzheimer’s disease, neural tube defects, non-insulin dependent diabetes.
  3. megaloblastic anemia
  4. impaired immune defense
  5. gastrointestinal disorders

The symptoms of vitamin B12 deficiency are fatigue, tingling sensation in the hands and feet, weakness, numbness and bloating.

Does your 23andme, Ancestry DNA, FTDNA raw data have FUT2 gene variant information?

CHIP Version FUT2 SNPs
23andMe (Use your 23andme raw data to know your FUT2 Variant)
v1 23andme Present
v2 23andme Present
v3 23andme Present
v4 23andme Present
V5 23andme (current chip) Present
AncestryDNA  (Use your ancestry DNA raw data to know your FUT2 Variant)
v1 ancestry DNA Present
V2 ancestry DNA (current chip) Present
Family Tree DNA  (Use your FTDNA raw data to know your FUT2 Variant)
OmniExpress microarray chip Present

Association with Vitamin B12 Needs:

In a study conducted on 1146 Indians, people with the G variants who were on a vegetarian diet were found to have significantly lower level of vitamin B12 when compared with people with the A variant.

In another study conducted on nearly 3000 people, people with the A variant of the gene were shown to have 44.2 pg/mL higher concentrations of vitamin B12.  




  • Moderate plasma Vitamin B12 levels



How can this information be used?

It is important to choose an appropriate diet based on the genetic profile[/idea]


For people with G variant (Decrease in plasma Vitamin B12 level)

Likely decrease in plasma vitamin B12 levels. Vegetarians are likely to have further decreased levels.

  • Include meat, fish, fortified soy products and fortified cereals in your diet to increase vitamin B12 levels in the body.
  • Since there is a genetic predisposition for lower levels of vitamin B12, it is recommended to consume more than the daily requirement of 2.4mcg of vitamin B12.


For people with A variant (Normal plasma Vitamin B12 level)

  • Increased likelihood for normal level of plasma vitamin B12 levels if the dietary intake is sufficient.




Nutrigenetics, fitness genetics, health genetics are all nascent but rapidly growing areas within human genetics. The information provided herein is based on preliminary scientific studies and it is to be read and understood in that context.”

Click here to upload your raw data

23andMe, Ancestry DNA, FTDNA and several others