Vitamin-B ₁₂-mangel im höheren lebensalter - Pathogenetische aspekte eines weit verbeiteten problems

verfasst von

A. Ströhle, M. Wolters, Andreas Hahn

Abstract

Vitamin B ₁₂ deficiency is a common problem in the elderly. If a serum cobalamin level of about 150 pmol/L (200 pg/mL) is considered normal, 10-15% of the elderly are deficient. Today, however, levels of 220-258 pmol/L (300-350 pg/mL) are regarded as desirable in the elderly, or more sensitive markers such as the blood concentration of homocysteine or methylmalonic acid are used. Then the prevalence of cobalamin deficiency increases to 43%. In the elderly, this is predominantly caused by atrophic gastritis type B. Atrophic gastritis results in insufficient gastric acid and pepsinogen secretion, leading to poor intestinal absorption of the cobalamin protein complexes from food. This applies to about 20-50% of the elderly. Reduced acid secretion, furthermore, leads to an alkalinisation of the small intestine which may result in bacterial overgrowth and a further decrease of the bioavailability of the vitamin. In addition, many drugs such as proton pump inhibitors or H ₂ receptor antagonists inhibit the intestinal absorption of vitamin B ₁₂. A moderately reduced vitamin B ₁₂ level is already associated with vascular disease and neurocognitive disorders such as depression and impaired cognitive performance. A poor vitamin B ₁₂ status, furthermore, is assumed to be involved in the development and progression of dementia (e.g. Alzheimer's disease). This applies especially to cases in which the folic acid status is reduced as well. In view of a possibly inadequate supply, the cobalamin status of elderly persons (≥60 years) should be regularly monitored and a general vitamin B ₁₂ supplementation (≥50 μg/d) be considered.

Organisationseinheit(en)

Abteilung Ernährungsphysiologie und Humanernährung
Institut für Lebensmittelwissenschaft und Humanernährung

Typ

Übersichtsarbeit

Journal

ERNAHRUNGS UMSCHAU

Band

51

Seiten

90-95+82

ISSN

0174-0008

Publikationsdatum

03.2004

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Medizin (sonstige), Ernährung und Diätetik