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Folic acid fortification and the prevalence of suboptimal vitamin B12 status without anemia and macrocytosis among older Americans in the National Health and Nutrition Examination Surveys (NHANES) 1991–1994 and 1999–2006
Author(s) -
Qi Yan Ping,
Do Ann,
Cogswell Mary E.,
Pfeiffer Christine M.,
Berry R. J.
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.237.2
Subject(s) - macrocytosis , national health and nutrition examination survey , medicine , vitamin b12 , folic acid , anemia , fortification , environmental health , pediatrics , population , food science , chemistry
To assess whether folic acid fortification has led to masking of the anemia of vitamin B12 deficiency, we compared the prevalence of suboptimal vitamin B12 status 1) without macrocytosis (mean cell volume <99 fL) and 2) without anemia (hemoglobin ≥13.0 g/dL for men and ≥12.0 g/dL for women) in adults age >50y from NHANES pre‐ and post‐ fortification. Vitamin B12 deficiency and depletion were defined, respectively, as serum vitamin B12 <148 pmol/L and 148 pmol/L –<258 pmol/L. We used multinomial logistic regression to compare the prevalence between surveys adjusting for age, sex, ethnicity, body mass index, C‐reactive protein and oral vitamin B12 supplement use. Pre‐ and post‐fortification prevalence of serum vitamin B12 deficiency without macrocytosis [4.5% v. 3.5%; OR(95%CI): 0.87(0.59–1.26)] and without anemia [4.3% v. 3.4%; OR(95%CI): 0.87(0.60–1.26)] remained unchanged. Pre‐ and post‐fortification prevalence of serum vitamin B12 depletion both without macrocytosis [27.0% v. 20.7%; OR(95%CI): 0.80(0.66–0.96)] and without anemia [26.4% v. 20.4%; OR(95%CI): 0.80(0.67–0.97)] decreased significantly. Our data show that the proportion of older adults with low vitamin B12 status 1) without macrocytosis and 2) without anemia did not increase following fortification, suggesting fortification was unlikely to have increased the risk for masking of vitamin B12 deficiency in this group. Research funded by CDC.