The methylation cycle refers to a cyclic process of methyl group transfer in cells. This process involves the transfer of the methyl group from one molecule to another and methylation occurs in DNA, RNA, proteins and other biological molecules. The methylation cycle is critical for the differentiation, development, and adaptation of cells to environmental changes. Methylation regulations in DNA, RNA, and proteins affect the regulation of gene expression, cell differentiation, cell cycle, and other biological processes. In cells, a balance must exist between methylation and demethylation. This balance ensures the normal functionality and epigenetic regulation of cells. Abnormal methylation or demethylation can contribute to cellular dysfunction and various diseases.
A number of vitamins and minerals are required for the healthy functioning of the methylation cycle. These nutrients serve as cofactors in the realization of methylation reactions and support the transfer of the methyl group. Some micronutrients also act as methyl group donors. Folate, vitamin B12 and B6, Betaine, Zinc, Magnesium and Choline are among the vitamins and minerals needed in the methylation cycle. The need for vitamins and minerals involved in the methylation cycle varies from person to person depending on the variants in the genes coding for the enzymes involved in the cycle. These genes need to be examined in order to determine the vitamin and mineral level an individual needs.