Genetic mutations like MTHFR, FOLR1, FOLR2, and VDR TAQ don’t just sit there—they cause vitamin deficiencies by…

Makes an enzyme that helps produce a form of folate used in the processing of homocysteine. Common variants are different from rare variants that cause severe MTHFR deficiency.

VDR encodes the vitamin D receptor, which helps regulate gene activity in response to active vitamin D. A receptor variant does not by itself mean receptors are absent or that the blood vitamin D level is low.

FOLR1 encodes folate receptor alpha, which helps cells take up folate and has an important role in folate transport at the brain’s barriers. Blood folate and folate availability in the nervous system are not identical measurements.

FOLR2 encodes folate receptor beta, a folate-binding protein expressed in particular cell types, including subsets of immune cells. It is distinct from the FOLR1 receptor and the SLC19A1 reduced folate carrier.