Subject(s)
Cimetidine/administration & dosage , Guanidines/administration & dosage , Organometallic Compounds , Peptic Ulcer/metabolism , Vitamin B 12/metabolism , Anti-Ulcer Agents/administration & dosage , Bismuth/administration & dosage , Humans , Intestinal Absorption , Intrinsic Factor/therapeutic use , Male , Vitamin B 12 Deficiency/prevention & controlABSTRACT
A patient with vitamin B12 deficiency and a true normal Schilling test result is presented. This patient could absorb chemically pure vitamin B12 normally but could not absorb protein-bound vitamin B12.
Subject(s)
Malabsorption Syndromes/diagnosis , Schilling Test , Vitamin B 12 Deficiency/diagnosis , Humans , Male , Middle AgedSubject(s)
Malabsorption Syndromes/diagnosis , Vagotomy/adverse effects , Vitamin B 12/metabolism , Administration, Oral , Circadian Rhythm , Cobalt Radioisotopes , Drainage , Gastric Juice/analysis , Gastric Juice/metabolism , Humans , In Vitro Techniques , Injections, Intramuscular , Insulin , Malabsorption Syndromes/blood , Malabsorption Syndromes/etiology , Malabsorption Syndromes/urine , Male , Protein Binding , Time Factors , Vitamin B 12/administration & dosage , Vitamin B 12/blood , Vitamin B 12/urineSubject(s)
Anemia, Hypochromic/blood , Erythrocytes , Folic Acid Deficiency/blood , Hemoglobins/analysis , Vitamin B 12 Deficiency/blood , Adult , Age Factors , Aged , Anemia, Hypochromic/diagnosis , Diagnosis, Differential , Female , Folic Acid Deficiency/diagnosis , Humans , Male , Sex Factors , Vitamin B 12 Deficiency/diagnosisSubject(s)
Statistics as Topic , Anemia, Hypochromic/blood , Folic Acid/blood , Humans , Vitamin B 12/bloodSubject(s)
Albumins , Charcoal , Vitamin B 12/analysis , Adsorption , Cobalt Isotopes , Gastric Juice/analysisABSTRACT
The binding of vitamin B(12) by human gastric juice has been found to be pH dependent. Maximum binding occurs between pH 6.5 and 10. Outside this pH range the vitamin B(12)-binding ability of human gastric juice decreases and at pH below 2 or above 12.2 this drops sharply to about 10 to 15% of the maximum. Three commercial hog intrinsic factors have been found to give a similar response to pH changes. The pH-dependent binder in human gastric juice has been shown to be intrinsic factor by the addition of intrinsic factor-blocking antibody. About 10% of vitamin B(12) bound by human gastric juice is not bound by intrinsic factor and is not pH dependent. The reduction in the vitamin B(12)-binding capacity of human gastric juice induced by an adverse pH is reversed by neutralization. The physiological and clinical significance of these observations is discussed and their relevance to various procedures in vitro noted.
