vitamin-b-12 and Tuberculosis

Mycobacterium tuberculosis is included among a select group of bacteria possessing the capacity for de novo biosynthesis of vitamin B12, the largest and most complex natural organometallic cofactor. The bacillus is also able to scavenge B12 and related corrinoids utilizing an ATP-binding cassette-type protein that is distinct from the only known bacterial B12-specific transporter, BtuFCD. Consistent with the inferred requirement for vitamin B12 for metabolic function, the M. tuberculosis genome encodes two B12 riboswitches and three B12-dependent enzymes. Two of these enzymes have been shown to operate in methionine biosynthesis (MetH) and propionate utilization (MutAB), while the function of the putative nrdZ-encoded ribonucleotide reductase remains unknown. Taken together, these observations suggest that M. tuberculosis has the capacity to regulate core metabolic functions according to B12 availability - whether acquired via endogenous synthesis or through uptake from the host environment - and, therefore, imply that there is a role for vitamin B12 in pathogenesis, which remains poorly understood.

Topics: Animals; Bacterial Proteins; Humans; Mycobacterium tuberculosis; Tuberculosis; Vitamin B 12

Topics: Anemia, Macrocytic; Anemia, Megaloblastic; Anemia, Pernicious; Animals; Folic Acid; Formates; Humans; Macrophages; Rats; Tuberculosis; Vitamin B 12; Vitamin B 12 Deficiency

The concentration of serum cobalamin (SB12) was estimated in tuberculous Nigerian patients so as to define the role of this vitamin in the pathogenesis of the anaemia of tuberculosis. Complete data in 147 infected subjects before and during treatment and in 50 asymptomatic blood donors revealed no significant difference between mean serum cobalamin (mean SB12) concentrations of patients of both sexes and the asymptomatic controls. No differences were demonstrated between mean SB12 of groups of patients subdivided on the basis of degree of anaemia. Moreover, there was no significant correlation between Hb and SB12. Mean SB12 was essentially similar in patients with localised (300.7 pmol/l) and disseminated (311.1 pmol/l) disease. In the 121 patients with pulmonary tuberculosis, mean SB12 of those with one affected lung (291.9 pmol/l) was not significantly different from those with infection of both lungs (303.5 pmol/l). Antituberculosis therapy did not cause a fall in mean SB12. This study does not provide evidence of any significant abnormality in serum cobalamin concentration in Nigerians suffering from localised or disseminated tuberculosis. There is, therefore, no rational basis for the widespread but costineffective practice of supportive oral or parenteral vitamin B12 therapy in the management of this disease.

Topics: Adolescent; Adult; Anemia; Child; Female; Humans; Male; Middle Aged; Nigeria; Tuberculosis; Vitamin B 12

Topics: Humans; Rifampin; Tuberculosis; Vitamin B 12

Topics: Aminosalicylic Acids; Carotenoids; Celiac Disease; Cholesterol; Feces; Folic Acid; Folic Acid Deficiency; Humans; Intestine, Small; Isoniazid; Lipid Metabolism; Malabsorption Syndromes; Male; Middle Aged; Radiography; Tuberculosis; Vitamin B 12

Topics: Acrylates; Adolescent; Adult; Aged; Aminosalicylic Acids; Anemia; Anemia, Hypochromic; Anemia, Macrocytic; Antitubercular Agents; Erythropoiesis; Female; FIGLU Test; Folic Acid; Folic Acid Deficiency; Humans; Imidazoles; Iron; Isoniazid; Male; Middle Aged; Streptomycin; Tuberculosis; Vitamin B 12

Topics: Alcoholism; Blood Sedimentation; Divorce; Dumping Syndrome; Duodenal Ulcer; Humans; Intestinal Absorption; Iron; Leukocyte Count; Mycobacterium tuberculosis; Nutrition Disorders; Social Conditions; Sputum; Stomach Ulcer; Sweden; Tuberculosis; Tuberculosis, Pulmonary; Vitamin A; Vitamin B 12

Topics: Adenoma; Adolescent; Aged; Anemia, Pernicious; Antibodies, Anti-Idiotypic; Antibody Formation; Autoantibodies; Autoimmune Diseases; Blood Protein Electrophoresis; Coombs Test; Diabetes Complications; Erythrocytes; Female; Humans; Male; Middle Aged; Pancreatitis; Rheumatic Heart Disease; Syphilis; Thymoma; Thyroid Diseases; Thyroid Neoplasms; Tuberculosis; Vitamin B 12

Topics: Adolescent; Adult; Aged; Anemia, Hypochromic; Anemia, Macrocytic; Antitubercular Agents; Blood; Bone Marrow Examination; Female; Folic Acid; Folic Acid Deficiency; Humans; Iron; Male; Middle Aged; Tuberculosis; Tuberculosis, Lymph Node; Tuberculosis, Osteoarticular; Tuberculosis, Pulmonary; Tuberculosis, Renal; Vitamin B 12

Topics: Acute Kidney Injury; Biological Assay; Blood Chemical Analysis; Glomerulonephritis; Kidney Diseases; Kidneys, Artificial; Mercury Poisoning; Nephritis; Nephritis, Interstitial; Postoperative Complications; Pyelonephritis; Renal Insufficiency; Solvents; Toxicology; Tuberculosis; Tuberculosis, Renal; Vitamin B 12; Wounds and Injuries

Topics: Adolescent; Aminosalicylic Acid; Aminosalicylic Acids; Antitubercular Agents; Blood Chemical Analysis; Child; Drug Therapy; Geriatrics; Humans; Infant; Isonicotinic Acids; Pharmacology; Rabbits; Research; Streptomycin; Tuberculosis; Tuberculosis, Pulmonary; Vitamin B 12

Topics: Appetite; Body Weight; Cobalt; Copper; Corrinoids; Drug Synergism; Drug Therapy; Geriatrics; Hematopoiesis; Humans; Iron; Liver Extracts; Lung Neoplasms; Lysine; Manganese; Tissue Extracts; Tuberculosis; Tuberculosis, Pulmonary; Vitamin B 12; Vitamin B Complex

Topics: Adenine Nucleotides; Adenosine Monophosphate; Heart Diseases; Humans; Pulmonary Heart Disease; Thiamine Pyrophosphate; Tuberculosis; Tuberculosis, Pulmonary; Vitamin B 12

Topics: Adolescent; Amino Acids; Corrinoids; Humans; Liver Diseases; Methionine; Sulfur; Tuberculosis; Urine; Vitamin B 12

Topics: Corrinoids; Diet; Diet Therapy; Drug Combinations; Hematinics; Reserpine; Thiamine; Tuberculosis; Vitamin B 12

Topics: Ascorbic Acid; Folic Acid; Humans; Liver Diseases; Niacinamide; Tuberculosis; Vitamin B 12; Vitamin B Complex; Vitamins

Topics: Corrinoids; Humans; Liver Diseases; Tuberculosis; Vitamin B 12

Topics: Anti-Bacterial Agents; Antibiotics, Antitubercular; Corrinoids; Niacin; Nicotinic Acids; Tuberculosis; Vitamin B 12

Topics: Blood; Corrinoids; Niacin; Nicotinic Acids; Serum; Tuberculosis; Tuberculosis, Pulmonary; Vitamin B 12

Topics: Corrinoids; Feeding and Eating Disorders; Humans; Tuberculosis; Tuberculosis, Pulmonary; Vitamin B 12