Objectives One-fifth of Canadian women of childbearing age have a red blood cell (RBC) folate below concentrations considered optimal for maximal neural tube defect risk reduction (<906 nmol/l). This study explored the determinants of RBC folate concentrations ≥906 nmol/l Canadian women.

Methods RBC folate concentrations from the nationally representative Canadian Health Measures Survey were assessed in women aged 15 to 45 years (N=1162). The population was described using frequencies and percentages. Sociodemographic, behavioural and clinical determinants of concentrations ≥906 nmol/l were examined using univariate and separate multiple logistic regression models controlling for age and household income.

Results More women with folate concentrations ≥906 nmol/l were evident in higher age groups (15 to 19 years (70.0%), 20 to 39 years (79.6%), 40 to 45 years (80.8%)) and income quartiles (74.7% (Q1), 76.8% (Q2), 80.2% (Q3), 86.3% (Q4)). Folic acid containing supplement users had a higher prevalence of concentrations ≥906 nmol/l (87.9%) than non- users (75.2%). Prevalence of concentrations ≥906 nmol/l rose with higher intake of fruit/vegetables (< once per day (64.7%), 1–2 times per day (74.2%) and >3 times per day (82.9%)) and grain products (< once per day (67.7%), 1–2 times per day (80.5%), >3 times per day (77.6%)). Detailed regression analysis results will be presented at the conference.

Interpretation These results will inform nutrition policies, particularly those related to folic acid fortification of select grains and preconception/prenatal folic acid supplementation recommendations for women of childbearing age. This will ultimately contribute to improving the health of Canadians and optimising infant health.