A progressive disease in which there is a decrease in the number and an increase in the size of red blood cells, resulting in weakness and gastrointestinal disturbances.
Disease of vitamin B12 deficiency. Characterized by low numbers of red blood cells that are poorly formed and by demyelination of the sheaths of nerve tracts.
Type of anemia characterized by defective red blood cell production, the presence of megaloblasts in the bone marrow, and deterioration of nerve tissue in the spinal cord. It is caused by a lack of intrinsic factor, essential for the absorption of vitamin Bi2, or to a deficiency of vitamin B12 in the diet. Symptoms include pallor, anorexia, weight loss, fever, weakness, and tingling of the extremities. Treatment includes the administration of vitamin B12, folic acid, and iron.
A disease, often occurring in middle or old age, in which red blood cells fail to develop normally because of vitamin B12 deficiency. Symptoms include fatigue, pallor, weakness, loss of appetite, dizziness. Vitamin BI2 injections control condition.
A blood disorder characterized by abnormally low numbers of red blood cells and caused by an inability to absorb vitamin B12, the cells lining a portion of the stomach make a substance called intrinsic factor that binds to vitamin Bl2 found in food. Only when combined with intrinsic factor can vitamin Bl2 be absorbed into the bloodstream from the intestine. People with pernicious anemia cannot produce intrinsic factor and become deficient in vitamin Bl2,which is needed for red blood cell production.
A form of anemia resulting from deficiency of vitamin B12. This in turn results either from failure to produce the substance (intrinsic factor) that facilitates absorption of B12 from the bowel or from dietary deficiency of the vitamin. Pernicious anemia is characterized by defective production of red blood cells and the presence of megaloblasts in the bone marrow. In severe forms the nervous system is affected . The condition is treated by injections of vitamin B12.
A chronic, macrocytic anemia marked by achlorhydria. It occurs most often in 40- to 80-year-old northern Europeans with fair skin but has been reported in other races and ethnic groups. It is rare in blacks and Asians.
The condition known as “pernicious anemia” is characterized by a reduction in the number of red blood cells, which can arise when the gastrointestinal tract fails to properly assimilate vitamin B-12 into the body.