Cancer and Vitamin B12: Does it Heal or Harm?

Vitamin B12 serves as one of the most prominent enzyme cofactors and is utilized in several different biological actions. As we gain an increased understanding on how this vitamin works, so does our understanding of its role in disease and illness. What is quite often the case for many health supplements, different sources make juxtaposing claims regarding vitamin B12. Some state it is an important anti-cancer agent, and others state that it may promote cancer risk. Despite these two very different claims, the truth may actually be that they are both correct.

As we know, all cells are governed by the genes within our DNA. What isn’t fully understood is the field of epigenetics, the phenomenon where select genes along the DNA chain are switched on or off. The practicality of this is what causes a heart cell to function differently than a muscle cell, or a lung cell to function differently than an eye cell. Although all contain identical DNA strands, it’s the selection of different genes that are activated which result in cell differentiation. This activation is also relevant in diseases such as cancer. There are select genes within our DNA whose purpose is to identify any DNA abnormalities (improper gene segments) and trigger a self-destruction mechanism to prevent cancer cell progression. Such genes are appropriately referred to as ‘tumor suppressor genes’.

One way genes are selectively switched on or off is through a process called DNA methylation. During this process, a methyl group (1 carbon and 3 hydrogen atoms) attaches itself to cytosine, a protein within the DNA strand. This methylation will change the chemical structure of the DNA thus altering the gene’s function. One of the most common source of a methyl group is methylcobalamin, also known as vitamin B12! Methylation of the DNA strand is an important part of genetic expression. However, if this process is increased or decreased, we may see negative results. Hypomethylation and hypermethylation both pose as potential problems. When there is hypomethylation or decreased methyl groups quite often seen in vitamin B12 deficiencies, certain genes may not be activated. If the tumor suppressor gene mentioned previously is one of these genes, it provides an environment where cancer cells can grow and mutate. This is a major reason why vitamin B12 is advocated as protective against cancer formation. Adversely, hypermethylation or an increase in methyl groups will also cause genetic dysfunction. Especially in cancer cells where genes are already dysfunctional, providing excess methyl groups to be used by oncogenes (genes that promote cancer formation) may increase the progression and severity of cancer that has already been diagnosed. Therefore, an important tool to prevent cancer is to maintain adequate vitamin B12 levels. However, in current cases of cancer, supplementation may need to be restricted. Three things every person should do in order to optimize their health is prevent vitamin deficiencies by eating a healthy full balanced diet, measure vitamin B12 levels if concerned about serum levels, and seek out professional advice on appropriate supplementation.