Folate

Folate is a water-soluble B vitamin that plays an important role in DNA and amino acid synthesis. Inadequate intake of folate eventually results in anemia and symptoms such as weakness, fatigue, heart palpitations, and shortness of breath.  Excessive intake of folic acid can mask the clinical symptoms of vitamin B12 deficiency and thus potentially delay diagnosis, resulting in an increased risk of permanent neurological damage.

Studies have shown that the use of supplements containing folic acid by women of childbearing age reduces the risk of neural tube defects (NTDs) in the developing fetus. Spina bifida is the most common NTD. Health Canada and the Public Health Agency of Canada recommend that all women who could become pregnant take a daily multivitamin supplement containing 0.4 mg of folic acid in addition to consuming a healthy diet. Even allowing for food fortification with folic acid, it would be difficult for most women to consume enough folic acid from diet alone to achieve the total amount recommended.

Dietary Sources

Major sources of food folate include dark green vegetables, citrus fruits and legumes. Folic acid is the synthetic form of folate found in supplements and fortified foods and is more readily absorbed by the body than food folate. It is commonly estimated that folic acid consumed alone (e.g., in supplement form) or with water is 100% available while folic acid added to foods is 85% available. Food folate is estimated to be only 50% available. In 1998, addition of folic acid to all white flour, enriched pasta and cornmeal sold in Canada became mandatory to help reduce the incidence of NTDs.

Assessment of Folate Status

Red blood cell (RBC) folate was selected as the measure of folate status because it is an indicator of long term folate status and is not affected by recent or temporary changes in dietary folate intake.

Notes:

Total household population aged 9 to 79, except those meeting the exclusion criteria.  For more information regarding the exclusion criteria, please refer to the  Canadian Health Measures Survey (CHMS) Data User Guide: Cycle 1.

Bootstrap weights included with the dataset were used to estimate the 95% confidence intervals for all means and percentiles assuming a student’s t-distribution with 11 degrees of freedom.

A chemiluminescent immunoassay (Immulite 2000 by DPC) was used to measure folate levels.

Data source: Canadian Health Measures Survey, Cycle 1.

Related Resources

Chapter on  Folate in Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (1998)

 Distribution of the household population by the concentration of red blood cell folate, by age and sex, Canada, 2007 to 2009

Prenatal Nutrition - Key Recommendations for Women

 Folate status of the population in the Canadian Health Measures Survey