Abstract
Objective: Mandatory folic acid fortification was implemented in Canada in 1998 to reduce the risk of neural tube defects (NTD). Our objective was to assess the relationship between socio-demographic factors and folate status in non-supplement-consuming Canadian women of childbearing age.
METHODS: Data on demographic factors, lifestyle factors, physical measures and red blood cell (RBC) folate concentration were collected from 1,008 non-supplement-consuming women aged 15-49 years in the Canadian Health Measures Survey (2007–2009). RBC folate ≥906 nmol/L was used as a cut-off for optimal folate status for protection from NTD.
RESULTS: Approximately 75% of non-supplement consuming women had an RBC folate concentration ≥906 nmol/L. Young age (15-19 years), White ethnicity, less than secondary education, lowest income adequacy, smoking and high body mass index were associated with a higher prevalence of lower folate status. After adjustment, only young age (adjusted odds ratio [OR] 1.99–95% confidence interval [CI]: 1.25–3.18) was associated with lower folate status. Less than secondary education (adjusted OR 5.66, 95% CI: 1.10–29.04) and lowest income adequacy (adjusted OR 4.77, 95% CI: 1.06–21.49) were associated with lower folate status in women aged 15-24 and 25-49 years, respectively.
CONCLUSIONS: Many risk factors for lower folate status identified before food fortification was implemented were not associated with folate status in our representative sample of non-supplement-consuming Canadian women. However, younger women, women aged 15-24 with less than secondary education and women aged 25-49 with low income adequacy remain at risk of lower folate status, supporting the continued promotion of folic acid supplement use to women of childbearing age.
Key Words: Folate, folic acid, fortification, neural tube defects, Canadian Health Measures Survey
Résumé
OBJECTIF: Appliqué au Canada depuis 1998, l’enrichissement obligatoire en acide folique vise à réduire le risque d’anomalies du tube neural (ATN). Notre objectif était d’évaluer la relation entre les facteurs sociodémographiques et le statut en folates chez les Canadiennes en âge de procréer ne consommant pas de suppléments.
MÉTHODE: Des données sur les facteurs démographiques, les facteurs liés au mode de vie, les indicateurs physiques et la concentration en folates érythrocytaires ont été recueillies auprès de 1 008 femmes de 15 à 49 ans ne consommant pas de suppléments et ayant participé à l’Enquête canadienne sur les mesures de la santé (2007–2009). Un seuil de folates érythrocytaires ≥906 nmol/L a servi à délimiter le statut optimal en folates qui protège contre les ATN.
RÉSULTATS: Environ 75 % des femmes ne consommant pas de suppléments avaient une concentration en folates érythrocytaires ≥906 nmol/L. La jeunesse (15-19 ans), l’ethnicité blanche, le fait d’avoir moins qu’un diplôme d’études secondaires, la catégorie inférieure de revenu adéquat, le tabagisme et un indice de masse corporelle élevé étaient associés à une prévalence accrue du faible statut en folates. Après correction, seule la jeunesse (rapport de cotes ajusté [RC] 1,99, intervalle de confiance de 95 % [IC]: 1,25–3,18) était associée au faible statut en folates. Le fait d’avoir moins qu’un diplôme d’études secondaires (RC ajusté 5,66, IC de 95 %: 1,10–29,04) et la catégorie inférieure de revenu adéquat (RC ajusté 4,77, IC de 95 %: 1,06–21,49) étaient associés au faible statut en folates chez les femmes de 15 à 24 ans et de 25 à 49 ans, respectivement.
CONCLUSIONS: De nombreux facteurs de risque de faible statut en folates, identifiés avant la mise en oeuvre de l’enrichissement des aliments, n’étaient pas associés au statut en folates dans notre échantillon représentatif de Canadiennes ne consommant pas de suppléments. Toutefois, les jeunes femmes, les femmes de 15 à 24 ans n’ayant pas terminé leurs études secondaires et les femmes de 25 à 49 ans dans la catégorie inférieure de revenu adéquat courent encore le risque d’avoir un faible statut en folates, ce qui justifie que l’on continue à promouvoir la supplémentation en acide folique chez les femmes en âge de procréer.
Mots Clés: folates, acide folique, aliments enrichis, anomalies du tube neural, Enquête canadienne sur les mesures de la santé
Footnotes
Acknowledgements: This work was funded by Health Canada and the Public Health Agency of Canada.
Conflict of Interest: None to declare.
References
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