In this blog, we’ll explore how your genetics influence B12 levels, symptoms of deficiency, and personalized strategies for optimization.

The methylation cycle is a vital biochemical process that affects the function of nearly every system in the body. 

It involves the transfer of a methyl group (CH₃) to various molecules, including DNA and proteins, which regulates gene expression and metabolic processes. Vitamin B12, in particular, is essential for this cycle, as it serves as a cofactor in reactions that help recycle homocysteine into methionine—an amino acid involved in protein synthesis and other crucial pathways, including DNA synthesis.

When the methylation cycle is disrupted—often due to genetic variants—it can lead to issues with B12 demand and metabolism. This is where genes like FUT2 and MTR come into play.

Key Genes Affecting B12 Levels

1. FUT2 (Fucosyltransferase 2):
This gene influences the ability of the body to absorb vitamin B12 through the gut microbiome. Variants in FUT2 can impair the production of certain gut bacteria that are necessary for B12 absorption. This may reduce the bioavailability of B12, even if it's present in the diet.

2. MTR (Methionine Synthase):
MTR is responsible for converting homocysteine to methionine in a methylation-dependent process. This conversion requires vitamin B12 as a cofactor. If B12 levels are low or its absorption is impaired (due to genetic variants), this vital step in the methylation cycle is compromised, potentially leading to elevated homocysteine levels, which are linked to cardiovascular issues, mood disturbances, and cognitive decline.

Relevant SNPs

1. FUT2 rs601338: This SNP in the FUT2 gene may affect gut microbiome functionality and B12 absorption, especially in individuals with certain variants who are at a higher risk of low B12 levels.
2. MTR A2756G (rs1805087): This SNP in the MTR gene increases enzyme activity and also raises the demand for B12. Without adequate B12 levels, individuals with this SNP may exhibit higher homocysteine levels and reduced overall methylation potential.

Symptoms of B12 Deficiency

• Fatigue and weakness
• Brain fog and memory issues
• Mood disturbances like depression

General Strategies for Optimizing B12 Levels

1. Diet:
Eat B12-rich foods like eggs, dairy products, and fortified plant-based products such as plant-based milks and cereals. 

2. Supplements:
Consider taking methylcobalamin, the bioavailable form of vitamin B12, especially if you have genetic variants like FUT2 or MTR that impair B12 absorption or utilization. Methylcobalamin is better absorbed and utilized by the body, making it an ideal supplement for those with these genetic variants.

3. Gut Health:
Since FUT2 influences the gut microbiome, maintaining a healthy gut is essential for effective B12 absorption. Include probiotics, prebiotics, and a fiber-rich diet to support gut health and improve B12 bioavailability.

In conclusion, understanding the genetic factors influencing your vitamin B12 metabolism—especially in relation to the methylation cycle—can help optimize your B12 levels. With Geneus DNA’s Exclusive package and our CARE persona, a DNA-based vitamin solution, you can get personalized insights and strategies to mitigate the effects of genetic variants like FUT2 and MTR and take proactive steps toward better health.