What genetic variants increase the risk of folate deficiency?

Folate or folic acid is a B vitamin (B9) essential for proper growth and development and for the production of red blood cells and white blood cells. It is also responsible for preventing changes to the DNA that can cause cancer, and aids in the conversion of the toxic amino acid homocysteine, which is produced during protein breakdown.

Folate is the form of vitamin B9 found naturally in food, while foods fortified with vitamin B9 such as cereals contain folic acid as the stable form.

Once absorbed, our bodies convert folate into several different forms. These processing steps involve an array of different enzymes. Genetic changes in two genes, MTHFD1 and MTHFR, which encode two of these processing enzymes, have been linked to an increased risk of folate deficiency.