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Vitamin B12 deficiency in the elderly.

Abstract

Vitamin B12 deficiency is estimated to affect 10%-15% of people over the age of 60, and the laboratory diagnosis is usually based on low serum vitamin B12 levels or elevated serum methylmalonic acid and homocysteine levels. Although elderly people with low vitamin B12 status frequently lack the classical signs and symptoms of vitamin B12 deficiency, e.g. megaloblastic anemia, precise evaluation and treatment in this population is important. Absorption of crystalline vitamin B12 does not decline with advancing age. However, compared with the younger population, absorption of protein-bound vitamin B12 is decreased in the elderly, owing to a high prevalence of atrophic gastritis in this age group. Atrophic gastritis results in a low acid-pepsin secretion by the gastric mucosa, which in turn results in a reduced release of free vitamin B12 from food proteins. Furthermore, hypochlorhydria in atrophic gastritis results in bacterial overgrowth of the stomach and small intestine, and these bacteria may bind vitamin B12 for their own use. The ability to absorb crystalline vitamin B12 remains intact in older people with atrophic gastritis. The 1998 recommended daily allowance for vitamin B12 is 2.4 micrograms, but elderly people should try to obtain their vitamin B12 from either supplements or fortified foods (e.g. fortified ready-to-eat breakfast cereals) to ensure adequate absorption from the gastrointestinal tract. Because the American food supply is now being fortified with folic acid, concern is increasing about neurologic exacerbation in individuals with marginal vitamin B12 status and high-dose folate intake.

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  • Publisher Full Text
  • Authors+Show Affiliations

    ,

    USDA Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts, USA. Baik_GI@HNRC.TUFTS.EDU

    Source

    Annual review of nutrition 19: 1999 pg 357-77

    MeSH

    Aging
    Biological Availability
    Diet
    Food
    Humans
    Nutritive Value
    Vitamin B 12
    Vitamin B 12 Deficiency

    Pub Type(s)

    Journal Article
    Review

    Language

    eng

    PubMed ID

    10448529

    Citation

    Baik, H W., and R M. Russell. "Vitamin B12 Deficiency in the Elderly." Annual Review of Nutrition, vol. 19, 1999, pp. 357-77.
    Baik HW, Russell RM. Vitamin B12 deficiency in the elderly. Annu Rev Nutr. 1999;19:357-77.
    Baik, H. W., & Russell, R. M. (1999). Vitamin B12 deficiency in the elderly. Annual Review of Nutrition, 19, pp. 357-77.
    Baik HW, Russell RM. Vitamin B12 Deficiency in the Elderly. Annu Rev Nutr. 1999;19:357-77. PubMed PMID: 10448529.
    * Article titles in AMA citation format should be in sentence-case
    TY - JOUR T1 - Vitamin B12 deficiency in the elderly. AU - Baik,H W, AU - Russell,R M, PY - 1999/8/17/pubmed PY - 1999/8/17/medline PY - 1999/8/17/entrez SP - 357 EP - 77 JF - Annual review of nutrition JO - Annu. Rev. Nutr. VL - 19 N2 - Vitamin B12 deficiency is estimated to affect 10%-15% of people over the age of 60, and the laboratory diagnosis is usually based on low serum vitamin B12 levels or elevated serum methylmalonic acid and homocysteine levels. Although elderly people with low vitamin B12 status frequently lack the classical signs and symptoms of vitamin B12 deficiency, e.g. megaloblastic anemia, precise evaluation and treatment in this population is important. Absorption of crystalline vitamin B12 does not decline with advancing age. However, compared with the younger population, absorption of protein-bound vitamin B12 is decreased in the elderly, owing to a high prevalence of atrophic gastritis in this age group. Atrophic gastritis results in a low acid-pepsin secretion by the gastric mucosa, which in turn results in a reduced release of free vitamin B12 from food proteins. Furthermore, hypochlorhydria in atrophic gastritis results in bacterial overgrowth of the stomach and small intestine, and these bacteria may bind vitamin B12 for their own use. The ability to absorb crystalline vitamin B12 remains intact in older people with atrophic gastritis. The 1998 recommended daily allowance for vitamin B12 is 2.4 micrograms, but elderly people should try to obtain their vitamin B12 from either supplements or fortified foods (e.g. fortified ready-to-eat breakfast cereals) to ensure adequate absorption from the gastrointestinal tract. Because the American food supply is now being fortified with folic acid, concern is increasing about neurologic exacerbation in individuals with marginal vitamin B12 status and high-dose folate intake. SN - 0199-9885 UR - https://www.unboundmedicine.com/medline/citation/10448529/full_citation L2 - http://arjournals.annualreviews.org/doi/full/10.1146/annurev.nutr.19.1.357?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -