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Yet, data are lacking on B<jats:sub>12<\/jats:sub>status in South Asian pregnant women in North America. We sought to determine B<jats:sub>12<\/jats:sub>status, using multiple biomarkers, in 1st and 2nd trimester pregnant women of South Asian and, for comparison, European ethnicity living in Vancouver, Canada. In this retrospective cohort study, total B<jats:sub>12<\/jats:sub>, holotranscobalamin (holoTC), methylmalonic acid (MMA), and total homocysteine concentrations were quantified in two routinely collected (mean gestational week: 11\u00b75 (range 8\u00b73\u201313\u00b79) and 16\u00b75 (range 14\u00b79\u201320\u00b79)), banked serum samples of 748 healthy pregnant South Asian (<jats:italic>n<\/jats:italic>371) and European (<jats:italic>n<\/jats:italic>377) women. South Asian pregnant women had significantly lower B<jats:sub>12<\/jats:sub>status than European pregnant women at both time points, as indicated by lower serum total B<jats:sub>12<\/jats:sub>and holoTC concentrations, and higher MMA concentrations (all<jats:italic>P<\/jats:italic>\u22640\u00b7001). The largest difference, which was substantial (Cohen\u2019s<jats:italic>d<\/jats:italic>\u22650\u00b75), was observed in mean serum total B<jats:sub>12<\/jats:sub>concentrations (1st trimester: 189 (95 % CI 180, 199)<jats:italic>v<\/jats:italic>. 246 (95 % CI 236, 257) pmol\/l; 2nd trimester: 176 (95 % CI 168, 185)<jats:italic>v<\/jats:italic>. 226 (95 % CI 216, 236) pmol\/l). Further, South Asian ethnicity was a significant negative predictor of B<jats:sub>12<\/jats:sub>status during pregnancy. South Asian women living in Vancouver have substantially lower B<jats:sub>12<\/jats:sub>status during early pregnancy. Future research identifying predictors and health consequences of this observed difference is needed to allow for targeted interventions.<\/jats:p>","DOI":"10.1017\/s0007114517002331","type":"journal-article","created":{"date-parts":[[2017,9,18]],"date-time":"2017-09-18T09:53:05Z","timestamp":1505728385000},"page":"454-462","update-policy":"https:\/\/doi.org\/10.1017\/policypage","source":"Crossref","is-referenced-by-count":17,"title":["Pregnant women of South Asian ethnicity in Canada have substantially lower vitamin B<sub>12<\/sub>status compared with pregnant women of European ethnicity"],"prefix":"10.1017","volume":"118","author":[{"given":"Theresa 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