We then used this model to estimate red blood cell folate concentrations for Community Intervention Project rs07 gold participants on the basis of their reported pill consumption, enabling an evaluation of the association between the estimates of red blood cell folate concentrations and risk of neural tube defects.The fact that MTHFR genotype was not determined for Community Intervention Project participants and that genotype can significantly affect the estimation of red blood cell folate concentrations necessitated development of additional models to estimate the distribution of genotypes among the Community Intervention Project participants.
