Articles on Medical Diseases and Conditions

Entries for the ‘Factor Deficiency Anemia’ Category


Pyridoxine (vitamin B6) is necessary for synthesis of D-aminolevulinic acid, a precursor of heme. Pyridoxine-deficient patients develop anemia with microcytic-hypochromic RBCs that can simulate chronic iron deficiency. Both hereditary and acquired (secondary) forms exist. The hereditary form is rare and the acquired form is uncommon, with the most frequently mentioned secondary type being due to […]

Folic Acid Deficiency

Folic acid (folate) is necessary for adequate synthesis of certain purines and pyrimidines, which, in turn, are precursors of cell DNA. Folate is also necessary for methionine synthesis, histadine catabolism, and metabolism of serine and glycine. Vitamin B12 converts inactive 5-methyltetrahydrofolate to tetrahydrofolate, which is able to transfer one-carbon groups. Folic acid deficiency causes a […]

Pernicious Anemia (PA)

Pernicious anemia (PA) typically is seen in Northern Europeans, but recently is being recognized more in African Americans and Hispanics. In Northern Europeans, age of onset is usually after age 40 years, with significantly higher incidence beginning at age 50-55 years. In African Americans, onset tends to occur several years earlier (especially in African-American women) […]

Vitamin B12 Deficiency

Vitamin B12 (cyanocobalamin) is necessary for adequate DNA synthesis through its role in folic acid metabolism. Vitamin B12 transforms metabolically inactive 5-methyl-tetrahydrofolate to tetrahydrofolate, which can then be converted to an active coenzyme. Vitamin B12 also acts as a single-carbon transfer agent in certain other metabolic pathways, such as metabolism of propionic acid. Most vitamin […]

Diagnosis of Chronic Iron Deficiency

The usual signals of iron deficiency are a decreased MCV (or anemia with a low-normal MCV) or elevated RDW. Hypochromia with or without microcytosis on peripheral blood smear is also suspicious. Conditions frequently associated with chronic iron deficiency (e.g., malabsorption, megaloblastic anemia, pregnancy, infants on prolonged milk feeding) should also prompt further investigation. The major […]

Laboratory Tests for Chronic Iron Deficiency

Several laboratory tests are commonly used to screen for or establish a diagnosis of chronic iron deficiency. The sequence in which abnormal test results appear is given in the box below. In a normal adult on a normal diet made iron deficient by repeated phlebotomy (for experimental reasons), it takes about 3 months before significant […]

Iron Deficiency

Iron deficiency may be produced in three ways: (1) iron intake not sufficient to replace normal iron losses, (2) iron not available for erythropoiesis despite adequate body iron, and (3) increased loss of body iron (blood loss) not adequately replaced by normal intake. Acute blood loss can usually be handled without difficulty if the bleeding […]

Iron Metabolism

Hemoglobin (Hb) contains about 70% of the body iron, and storage iron accounts for most of the remainder. One gram of Hb contains 3.4 mg of iron, and 1 ml of packed red blood cells (RBCs) contains about 1 mg of iron. Iron intake averages about 10 mg/day, of which about 10% is absorbed. Iron […]