A genetic variation in the gene for the protein dihydrofolate reductase (DHFR) that is necessary to utilize folic acid (a synthetic form of the B vitamin folate found in supplements and fortified food), increases the risk for breast cancer in multivitamin users and, when present in mothers who used folic acid supplements during pregnancy, increases the risk for cancer of the eye of their children. The aim of the proposed research is to understand how a common genetic variation in the gene for DHFR affects the function of this protein and the ability of the body to use folic acid.

NCT03319979

Conditions

1. Characterize rs70991108 Polymorphism of DHFR Gene

Characterize rs70991108 Polymorphism of DHFR Gene A 19bp deletion polymorphism of intron 1 of dihydrofolate reductase (DHFR 19bpdel) increases the risk for breast cancer, and retinoblastoma of the offspring, in folic acid supplement users.

In this two-arm, double-blind randomized pilot study, the investigators will recruit 60 generally healthy, low-risk pregnant women aged 19-42 years living in Vancouver, Canada. Participants will be randomized to supplement with either 0.6 mg/day folic acid or an equimolar dose (0.625 mg/day) of (6S)-5-methyltetrahydrofolic acid for 16-weeks of their pregnancy. Randomization will occur at 8-21 weeks gestation (after neural tube closure) to reduce the risk of harm should the natural folate prove less effective. All participants will also receive a prenatal multivitamin not containing any form of folate, to ensure adequacy of other nutrients (e.g. iron) required during pregnancy. Three-hour fasting venous blood samples will be collected at baseline and endline to measure serum and red blood cell folate, unmetabolized folic acid and other related biomarkers. Women will be given the option to continue supplementing until 1-week postpartum, and provide a small (3mL) breastmilk sample in order to measure differences in folates in breastmilk. These pilot data will be used to inform a definitive trial regarding the most effective form of folate supplementation for mothers and their babies.

NCT04022135

Conditions

1. Pregnancy

Interventions

1. Dietary Supplement: Folic acid
2. Dietary Supplement: (6S)-5-methyltetrahydrofolic acid

Gene variant assessment of MTHFR (677 C>T, rs1801133, and 1298 A>C, rs1801131) and DHFR (rs1643649 and rs70991108) and differences in DNA methylation.