1. Vitamin B-12 and neural tube defects: the Canadian experience.
- Author
-
Thompson MD, Cole DE, and Ray JG
- Subjects
- Adult, Biological Availability, Biomarkers blood, Canada, Female, Flour, Folic Acid administration & dosage, Food, Fortified, Humans, Methylmalonic Acid blood, Neural Tube Defects epidemiology, Neural Tube Defects etiology, Pregnancy, Randomized Controlled Trials as Topic, Transcobalamins, Vitamin B 12 pharmacokinetics, Vitamin B 12 Deficiency complications, Vitamin B Complex administration & dosage, Vitamin B Complex blood, Neural Tube Defects prevention & control, Nutritional Status, Vitamin B 12 administration & dosage, Vitamin B 12 blood, Vitamin B 12 Deficiency epidemiology
- Abstract
Although early epidemiologic studies showed a protective effect of adequate maternal folic acid (FA) status against neural tube defects (NTDs), the role of adequate vitamin B-12 nutrition in the putative reduction of NTD frequency has remained uncertain. Evaluating vitamin B-12 status was complicated by the need to control for altered FA status after fortification in Canada. More recent studies have made use of better biomarkers of vitamin B-12 status, including methylmalonic acid and holotranscobalamin (holoTC). HoloTC provides a useful measure of vitamin B-12 status because it represents the bioavailable fraction of circulating vitamin B-12. By assessing bioavailable vitamin B-12 status in a large Canadian cohort accrued before and after FA fortification, we found a 3-fold increase in the risk of NTDs in mothers who had vitamin B-12 status in the lower quartile, regardless of FA fortification. Our work suggests that vitamin B-12 fortification, analogous to the FA fortification program, may reduce NTDs more than FA fortification alone. A multicenter randomized controlled trial comparing periconceptional vitamin B-12 in combination with FA against FA alone is warranted.
- Published
- 2009
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