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The prevalence of low serum vitamin B-12 status in the absence of anemia or macrocytosis did not increase among older U.S. adults after mandatory folic acid fortification.

ABSTRACT: Whether folic acid fortification and supplementation at the population level have led to a higher prevalence of vitamin B-12 deficiency in the absence of anemia remains to be examined among a nationally representative sample of older U.S. adults. We assessed the prevalence of low vitamin B-12 status in the absence of anemia or macrocytosis before and after fortification among adults aged >50 y using cross-sectional data from the NHANES 1991-1994 (prefortification) and 2001-2006 (postfortification). We compared the prefortification and postfortification prevalence of multiple outcomes, including serum vitamin B-12 deficiency (<148 pmol/L) and marginal deficiency (148-258 pmol/L) with and without anemia (hemoglobin <130 g/L for men, <120 g/L for women) and with and without macrocytosis (mean cell volume >100 fL) using multinomial logistic regression, adjusting for age, sex, ethnicity, body mass index, C-reactive protein, and vitamin B-12 supplement use. Prefortification and postfortification serum vitamin B-12 deficiency without anemia [4.0 vs. 3.9%; adjusted prevalence ratio (aPR) (95% CI): 0.98 (0.67, 1.44)] or without macrocytosis [4.2 vs. 4.1%; aPR (95% CI): 0.96 (0.65, 1.43)] remained unchanged. Marginal deficiency without anemia [25.1 vs. 20.7%; aPR (95% CI): 0.82 (0.72, 0.95)] or without macrocytosis [25.9 vs. 21.3%; aPR (95% CI): 0.82 (0.72, 0.94)] were both significantly lower after fortification. After fortification, higher folic acid intake was associated with a lower prevalence of low serum B-12 status in the absence of anemia or macrocytosis. Results suggest that the prevalence of low serum B-12 status in the absence of anemia or macrocytosis among older U.S. adults did not increase after fortification. Thus, at the population level, we found no evidence to support concerns that folic acid adversely affected the clinical presentation of vitamin B-12 deficiency among older adults.

SUBMITTER: Qi YP

PROVIDER: S-EPMC5291239 | biostudies-literature | 2014 Feb

REPOSITORIES: biostudies-literature

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The prevalence of low serum vitamin B-12 status in the absence of anemia or macrocytosis did not increase among older U.S. adults after mandatory folic acid fortification.

Qi Yan Ping YP Do Ann N AN Hamner Heather C HC Pfeiffer Christine M CM Berry Robert J RJ

The Journal of nutrition 20131204 2

Whether folic acid fortification and supplementation at the population level have led to a higher prevalence of vitamin B-12 deficiency in the absence of anemia remains to be examined among a nationally representative sample of older U.S. adults. We assessed the prevalence of low vitamin B-12 status in the absence of anemia or macrocytosis before and after fortification among adults aged >50 y using cross-sectional data from the NHANES 1991-1994 (prefortification) and 2001-2006 (postfortificatio ...[more]

PMID: 24306216

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Project description:BackgroundMegaloblastic anemia (MBA), also known as macrocytic anemia, is a type of anemia characterized by decreased number of RBCs as well as the presence of unusually large, abnormal and poorly developed erythrocytes (megaloblasts), which fail to enter blood circulation due to their larger size. Lack of vitamin-B12 (VB12) and / or folate (Vitamin-B9, VB9) with elevated homocysteine is the key factor responsible for megaloblastic anemia. Prior studies have demonstrated the induction of apoptosis in these abnormal under-developed erythrocytes. However, it is not clear whether this apoptosis induction is due to elevated p53 level or due to any other mechanism. Furthermore, it is also not fully known whether decreased vitamin-B12 and / or folate are responsible for apoptosis induction mediated by p53 in pre-erythroblasts.MethodsLevels of serum VB9, VB12 and homocysteine in 50 patients suffering from MBA were compared with 50 non-megaloblastic anemia control subjects, who were referred by the clinicians for bone marrow examination for medical conditions other than MBA. Next, we have measured the p53 expression in the paraffin embedded blocks prepared from bone marrow biopsy, using immunohistochemistry, and the expression levels correlated with VB9 and VB12 levels.ResultsOut of 50 MBA patients 40 (80%) and 44 (88%) subjects had very low VB12 and VB9 levels respectively. In contrast, only 2 (4%) and 12 (24%) non-megaloblastic anemia controls, out of 50 subjects, had low VB12 and VB9 respectively. Correlating with low vitamin B9 and B12, the homocysteine levels were high in 80% cases. But, only 20% non-megaloblastic controls exhibited high homocysteine in plasma. Immunohistochemical analysis for p53 expression showed a significantly high level of expression in MBA cases and no-or very low-expression in control subjects. Our correlation studies comparing the VB12 and VB9 levels with p53 expression concludes unusually high p53 levels in patients suffering from VB12 and VB9 deficiency induced MBA compared to control subjects not suffering from MBA.ConclusionTumor protein p53 is the key protein expressed heavily in the bone marrow biopsies of patients suffering from VB12 and VB9 deficiency induced MBA but not in control subjects. Hence, p53 expression could be used as a surrogate marker for confirming the VB9 and VB12 induced MBA.

Dataset Information

The prevalence of low serum vitamin B-12 status in the absence of anemia or macrocytosis did not increase among older U.S. adults after mandatory folic acid fortification.

Publications

The prevalence of low serum vitamin B-12 status in the absence of anemia or macrocytosis did not increase among older U.S. adults after mandatory folic acid fortification.

Similar Datasets

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