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Cobalamin absorption and serum homocysteine and methylmalonic acid in elderly subjects with low serum cobalamin
Author(s) -
Joosten E.,
Pelemans W.,
Devos P.,
Lesaffre E.,
Goossens W.,
Criel A.,
Verhaeghe R.
Publication year - 1993
Publication title -
european journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.904
H-Index - 84
eISSN - 1600-0609
pISSN - 0902-4441
DOI - 10.1111/j.1600-0609.1993.tb00600.x
Subject(s) - cobalamin , methylmalonic acid , homocysteine , medicine , vitamin b12 , gastroenterology
We prospectively studied 41 consecutive elderly patients with serum cobalamin (vitamin B 12 ) levels lower than 125 pmol/l. The protein‐bound cobalamin absorption test (PBAT) was performed in 34 of them and in 27 selected elderly control patients. The lower decision limit was 0.18% and an abnormal test was detected in only 9 (26%) of the 34 patients with low serum cobalamin level. When the PBAT was compared to the Schilling (Dicopac method) test, a concordant result was found in 80 %. Serum methylmalonic acid and/or total homocysteine concentrations were elevated in 75% (26/35) of the patients with low serum cobalamin levels but also in 30% (5/17) of the control patients. Of the 12 and 9 cobalamin‐deficient patients with elevated serum levels of methylmalonic acid and homocysteine, normalization after cobalamin therapy was obtained in 11 and 5 respectively. In conclusion, determination of serum metabolites and their response to cobalamin therapy are a sensitive index of significant cobalamin deficiency and a useful means of distinguishing between cobalamin and folate deficiency. The PBAT offers little advantage over the Schilling test in diagnosing cobalamin malabsorption in elderly patients.