HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (Publish Ahead of Print[PDF]) All Versions of this Article: 89/2/693S    most recent ajcn.2008.26947Av1 Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Allen, L. H Search for Related Content PubMed PubMed Citation Articles by Allen, L. H Agricola Articles by Allen, L. H

How common is vitamin B-12 deficiency?^1,2,3

¹ From the US Department of Agriculture, ARS Western Human Nutrition Research Center, University of California, Davis, Davis, CA.

² Presented at the symposium "Is It Time for Mandatory Vitamin B-12 Fortification in Flour?" held at Experimental Biology 2008, San Diego, CA, 8 April 2008.

³ Reprints not available. Address correspondence to LH Allen, USDA, ARS Western Human Nutrition Research Center, 430 West Health Sciences Drive, University of California, Davis, Davis, CA 95616. E-mail: lindsay.allen{at}ars.usda.gov

ABSTRACT

In considering the vitamin B-12 fortification of flour, it is important to know who is at risk of vitamin B-12 deficiency and whether those individuals would benefit from flour fortification. This article reviews current knowledge of the prevalence and causes of vitamin B-12 deficiency and considers whether fortification would improve the status of deficient subgroups of the population. In large surveys in the United States and the United Kingdom, 6% of those aged 60 y are vitamin B-12 deficient (plasma B-12 < 148 pmol/L), with the prevalence of deficiency increasing with age. Closer to 20% have marginal status (plasma B-12: 148–221 pmol/L) in later life. In developing countries, deficiency is much more common, starting in early life and persisting across the life span. Inadequate intake, due to low consumption of animal-source foods, is the main cause of low serum B-12 in younger adults and likely the main cause in poor populations worldwide; in most studies, serum vitamin B-12 concentration is correlated with intake of this vitamin. In older persons, food-bound cobalamin malabsorption becomes the predominant cause of deficiency, at least in part due to gastric atrophy, but it is likely that most elderly can absorb the vitamin from fortified food. Fortification of flour with vitamin B-12 is likely to improve the status of most persons with low stores of this vitamin. However, intervention studies are still needed to assess efficacy and functional benefits of increasing intake of the amounts likely to be consumed in flour, including in elderly persons with varying degrees of gastric atrophy.

This article has been cited by other articles:

				M. D Thompson, D. E. Cole, and J. G Ray Vitamin B-12 and neural tube defects: the Canadian experience Am. J. Clinical Nutrition, February 1, 2009; 89(2): 697S - 701S. [Abstract] [Full Text] [PDF]

				A D. Smith and H. Refsum Vitamin B-12 and cognition in the elderly Am. J. Clinical Nutrition, February 1, 2009; 89(2): 707S - 711S. [Abstract] [Full Text] [PDF]

				J. Selhub, M. S. Morris, P. F Jacques, and I. H Rosenberg Folate-vitamin B-12 interaction in relation to cognitive impairment, anemia, and biochemical indicators of vitamin B-12 deficiency Am. J. Clinical Nutrition, February 1, 2009; 89(2): 702S - 706S. [Abstract] [Full Text] [PDF]

				R. Green Is it time for vitamin B-12 fortification? What are the questions? Am. J. Clinical Nutrition, February 1, 2009; 89(2): 712S - 716S. [Abstract] [Full Text] [PDF]