intrinsic-factor and Nervous-System-Diseases

At one time, the diagnosis of a deficiency of vitamin B12 or folate was considered to be relatively straightforward. As knowledge has accumulated, the limitations of such tests as serum vitamin level measurements and the Schilling test have become apparent. With the development of newer tests, atypical and subclinical deficiency states have been recognized. In this review, available tests used in the diagnosis of vitamin B12 and folate deficiency are discussed, and a rational approach to the diagnosis of these deficiency states is presented.

Topics: Antibodies; Clinical Laboratory Techniques; Clinical Trials as Topic; Decision Trees; Diagnosis, Differential; Erythrocytes; Folic Acid Deficiency; Hematologic Diseases; Homocysteine; Humans; Intrinsic Factor; Methylmalonic Acid; Nervous System Diseases; Parietal Cells, Gastric; Primary Health Care; Schilling Test; Vitamin B 12; Vitamin B 12 Deficiency

Topics: Anemia, Megaloblastic; Humans; Intrinsic Factor; Nervous System Diseases; Vitamin B 12; Vitamin B 12 Deficiency

This monograph on the clinical chemistry of vitamin B12 reviews the literature on daily requirements, methods for measurement, the effects of drugs on vitamin B12 metabolism absorption, pregnancy, clinical conditions associated with vitamin B12 deficiency, errors of metabolism, and reactions to vitamin therapy. Although only very small quantities of vitamin B12 are required to satisfy the daily requirement, a sufficient supply is stored in the liver to meet normal requirements for at least a 3-year period. A number of drugs are known to affect the absorption of vitamin B12, including neomycin, potassium chloride, p-aminosalicylic acid, and colchicine. Significantly reduced serum concentrations of vitamin B12 have been noted in users of oral contraceptives (OCs), although concentrations still remain within the limits of normal. It appears that the vitamin B12 level in OC users reestablishes itself at a different and somewhat lower level. Vitamin B12 binding protein appears to remain unchanged. A vitamin B12 deficiency is unusual in pregnant women who consume a normal, varied diet. On the other hand, lactating women whose diets are low in animal protein and dairy products may have problems providing enough vitamin B12 to meet their own and their infant's needs; supplementary oral vitamins should be considered.

Topics: Absorption; Adult; Alcoholism; Anemia, Pernicious; Ascorbic Acid; Autoantibodies; Biguanides; Biological Transport; Chemical Phenomena; Chemistry; Chlorpromazine; Contraceptives, Oral; Diet; Female; Gastrectomy; Gastritis; Humans; Intrinsic Factor; Malabsorption Syndromes; Male; Metabolism, Inborn Errors; Middle Aged; Neoplasms; Nervous System Diseases; Nitrous Oxide; Nutritional Requirements; Pancreatic Diseases; Parasitic Diseases; Pregnancy; Pregnancy Complications; Transcobalamins; Vitamin B 12; Vitamin B 12 Deficiency

Topics: Adult; Aged; Anemia, Pernicious; Child, Preschool; Europe; Female; History, 19th Century; History, 20th Century; Humans; Infant; Intrinsic Factor; Male; Middle Aged; Nervous System Diseases; United States; Vitamin B 12

It is believed that Pernicious anaemia (PA) is more common in the West. We postulate however that in India PA is probably an important aetiological factor as a cause of Vitamin B12 deficiency in patients having neurological disease.. To investigate the aetiological factors resulting in Vitamin B12 (Vit B12) deficiency in patients with subacute combined degeneration (SACD) and other neurological manifestations.. We undertook a prospective study of 50 patients, all clinically suspected to have Vit B12 deficiency; they were investigated clinically, haematologically, biochemically and radiologically.. There was a dominance of males (41 of 50) with the majority in the age group of more than 40 years of age. There was no correlation between the socio-economic and dietary status on the one hand and the clinical manifestation on the other. Anti intrinsic factor antibodies (AIFAB) were positive in 19 of 50 patients (38%) and anti parietal cell antibodies (APCAB) were positive in 28 of 50 (56%) patients.. We conclude that Pernicious anaemia is an important cause of various neurological manifestations including SACD in the Vitamin B12 deficient population in the age group of more than 40 years, irrespective of the socio-economic and dietary status in the Indian subcontinent. It is supported by the presence of AIFAB or APCAB in this group.

Topics: Adult; Aged; Anemia, Pernicious; Autoantibodies; Cross-Sectional Studies; Diet, Vegetarian; Female; Humans; India; Intrinsic Factor; Male; Middle Aged; Nervous System Diseases; Neurologic Examination; Parietal Cells, Gastric; Risk Factors; Subacute Combined Degeneration; Vitamin B 12 Deficiency

Topics: Adult; Aged; Anemia, Pernicious; Female; Gastrectomy; Gastrointestinal Diseases; Humans; Ileum; Intestinal Absorption; Intrinsic Factor; Male; Mental Disorders; Middle Aged; Nervous System Diseases; Schilling Test; Vitamin B 12