ascorbic-acid and Anemia--Megaloblastic

1. Low serum B12 levels can be measured with considerable precision by microbiological assay with the Euglena gracilis assay and B12 deficiency can be recognised with a high level of consistency by either the Euglena or L. leichmannii assays. Either method is ideally suited for the assay of large numbers of specimens. The Lactobacillus leichmanii technique requires preliminary extraction of protein and it has been suggested that this may be a source of inaccuracy. 2. The radioisotope dilution assay should be the ideal method of measuring B12 levels in small or moderate numbers of specimens for it is a simple method that can be carried out in any laboratory with suitable counting equipment. After many false starts the conditions required for accurate assay are now understood. Each of 40 to 50 radioisotopic dilution techniques that have been introduced claims to be capable of differentiating B12 deficiency from control subjects but the reported correlations between the actual levels found in the two different assays are variable and the levels may be much higher with some radioisotopic methods. 3. The subnormal serum levels which are found in pernicious anaemia with all these techniques indicate severe reduction of the liver B12 level. A low serum B12 level in other conditions has, in the absence of associated folate or iron deficiency, the same significance. If the fall in the serum B12 level is associated with folate or iron deficiency, the tissue B12 levels are usually reduced but not to the low levels found in B12 deficiency states. 4. In practice, a subnormal B12 level is a valuable pointer not only to unsuspected pernicious anaemia but also to other gastrointestinal or nutritional disorders. The significance of a fall in the B12 level can only be understood if its cause is defined by a full clinical and gastroenterological investigation. 5. Falsely low serum B12 levels are found under certain iatrogenic conditions and B12 levels may be normal in spite of cellular deficiency of B12 under the rare circumstances of pernicious anaemia being associated with chronic myeloid leukaemia or when there is deficiency of TC 2.

Topics: Anemia, Megaloblastic; Anemia, Pernicious; Ascorbic Acid; Biological Assay; Bone Marrow; Bone Marrow Cells; Carrier Proteins; Deoxyuridine; Euglena gracilis; Female; Folic Acid Deficiency; Humans; Intrinsic Factor; Lactobacillus; Leukemia, Myeloid; Male; Pregnancy; Pregnancy Complications; Radioisotope Dilution Technique; Transcobalamins; Vitamin B 12; Vitamin B 12 Deficiency

Topics: Aged; Anemia, Megaloblastic; Ascorbic Acid; Ascorbic Acid Deficiency; Diet; Humans; Male; Pancytopenia; Treatment Outcome; Vitamin B 12; Vitamins

Possible interactions between folic acid (folate) and ascorbic acid (AA) have been suspected because megaloblastic anemia is occasionally observed in scorbutic patients, and it may or may not respond to folate treatment. Male weanling guinea pigs were fed diets containing high levels of folate and AA or diets deficient in one or both vitamins. A total of 36 animals, including 9 controls, were studied. When anorexia began to appear in the deficient groups, all animals were killed by exsanguination, and tissue samples (blood, liver, adrenal, kidney, spleen, and intestinal mucosa) were removed for AA and folate analyses. Folate and AA deficiency lowered tissue folate and AA levels, respectively. AA deficiency, either alone or in combination with folate restriction, did not affect tissue folate levels, nor did AA deficiency significantly exacerbate the anemia and leukopenia caused by folate deficiency. However, there was an unexpected decrease in AA levels in the liver and adrenal glands with folate deficiency. Although AA does not appear to be needed for normal folate metabolism, the lower AA levels associated with a folate deficiency are indicative of an interaction between the two vitamins.

Topics: Anemia, Megaloblastic; Animals; Ascorbic Acid; Ascorbic Acid Deficiency; Folic Acid; Folic Acid Deficiency; Guinea Pigs; Hematocrit; Hemoglobins; Leukopenia; Male; Organ Specificity; Tissue Distribution

Reports concerning the interaction between steroidal contraceptives (the combined pill) and vitamins indicate that in users the mean serum-vitamin-A level is raised and the mean serum-vitamin-B2 (riboflavine), vitamin-B6 (pyridoxine), vitamine-C, folic-acid, and vitamin-B12 levels are reduced. Other vitamins have been insufficiently studied for comment. Biochemical evidence of co-enzyme deficiency has been reported for vitamin B2, vitamin B6, and folic acid. Clinical effects due to vitamin deficiency have been described for vitamin B6--namely, depression and impaired glucose tolerance. Folic-acid deficiency with megaloblastic anaemia has been reported in only 21 cases.

Topics: Anemia, Megaloblastic; Ascorbic Acid; Avitaminosis; Coenzymes; Contraceptives, Oral; Depression; Female; Folic Acid Deficiency; Glucose Tolerance Test; Humans; Pyridoxine; Riboflavin; Vitamin A; Vitamin B 12; Vitamin B 6 Deficiency

Topics: Anemia, Macrocytic; Anemia, Megaloblastic; Ascorbic Acid; Folic Acid; Formates; Humans; Leucovorin; Male; Middle Aged; Scurvy; Tetrahydrofolates

Topics: Anemia; Anemia, Macrocytic; Anemia, Megaloblastic; Anemia, Pernicious; Ascorbic Acid; Folic Acid; Humans; Metabolism; Vitamin B 12

Topics: Anemia; Anemia, Macrocytic; Anemia, Megaloblastic; Ascorbic Acid; Humans; Osteoporosis; Scurvy

Topics: Anemia, Macrocytic; Anemia, Megaloblastic; Anemia, Pernicious; Ascorbic Acid; Ascorbic Acid Deficiency; Folic Acid; Humans; Vitamin B 12; Vitamin B 12 Deficiency

Topics: Anemia, Macrocytic; Anemia, Megaloblastic; Ascorbic Acid; Folic Acid; Geriatrics; Hemoglobinometry; Humans; Reticulocytes; Vitamin B 12; Vitamin B Deficiency

Topics: Anemia; Anemia, Macrocytic; Anemia, Megaloblastic; Ascorbic Acid; Blood Transfusion; Child; Diarrhea; Folic Acid; Humans; Infant; Infections; Nutrition Disorders

Topics: Anemia; Anemia, Macrocytic; Anemia, Megaloblastic; Ascorbic Acid; Asian People; Blood Chemical Analysis; Bone Marrow Examination; Dietary Carbohydrates; Dietary Proteins; Folic Acid; Folic Acid Deficiency; Leucovorin; Lipids; Myanmar; Vitamin B 12

Topics: Anemia; Anemia, Macrocytic; Anemia, Megaloblastic; Ascorbic Acid; Female; Folic Acid; Humans; Postpartum Period; Puerperal Disorders

Topics: Adult; Anemia; Anemia, Megaloblastic; Ascorbic Acid; Humans; Scurvy

Topics: Anemia; Anemia, Macrocytic; Anemia, Megaloblastic; Animals; Ascorbic Acid; Folic Acid; Folic Acid Deficiency; Scurvy; Tracheophyta

Topics: Anemia; Anemia, Macrocytic; Anemia, Megaloblastic; Ascorbic Acid; Humans; Pregnancy; Vitamin B 12

Topics: Anemia; Anemia, Megaloblastic; Ascorbic Acid; Folic Acid; Humans; Tracheophyta; Vitamins