Iron, B12, and Folate Deficiency Anemia

Anemia due to Vit B12 deficiency and folate deficiency

• Both vitamins are essential for DNA synthesis • Decreased erythrocytes production • Erythrocytes that are produced are abnormally large (megaloblastic red cells) • Other blood cells also abnormal (WBC and platelet abnormalities) • Anemia due to vitamin B12 and folate deficiency known as megaloblastic or macrocytic anemia

Folate deficiency

• Due to decreased dietary intake of folate • Folate stores can become depleted within 4 months if dietary intake inadequate • Occurs in people who rarely eat uncooked green vegetables, alcoholism, chronic hemolytic anemias, women who are pregnant, and malabsorptive diseases of the small bowel (e.g., celiac disease)

Vitamin B12 deficiency

• Inadequate dietary intake rare • Malabsorption from GI tract more common (Chron's disease, baratric surgery, gastrectomy, chronic use of proton pump inhibitors, use of metformin, absence of intrinsic factor*) • Occurs in conditions such as Crohn's disease; after ileal resection, bariatric surgery, or gastrectomy; chronic use of proton pump inhibitors, use metformin for diabetes, and absence of intrinsic factor • Anemia associated with B12 deficiency due to absence of intrinsic factor known as pernicious anemia - usually occurs in 50 year olds and older

Iron Deficiency Anemia: Management

• Investigate cause of iron deficiency • Increase dietary iron intake • Oral iron supplementation ◦ Daily supplementation for 6-12 months to replenish iron stores ◦ Take on empty stomach (1h before meals or 2h after meals). If taking with food, can decrease absorption by 40-50% ◦ Side effects: nausea, vomiting, gastritis, heartburn, constipation, black stools, diarrhea • May need IV iron supplementation - used if Po isn't working • Liquid preparation - stains teeth; straw or spoon and then rinse mouth

Megaloblastic Anemias: clinical manifestations

• Mild cases of megaloblastic anemias may produce few signs and symptoms • Often diagnosed with routine CBC • Symptoms associated with folate deficiency develop more rapidly • Severe vitamin B12 deficiency: marked anemia; smooth, shiny, red tongue; and neurologic deficits (loss of proprioception, peripheral neuropathy, paresthesias, ataxia, altered balance) • Symptoms resolve with correction of deficiency

Iron Deficiency Anemia...General

• Most common type of anemia • Dietary iron intake inadequate for hemoglobin synthesis - foods that inhibit the absorption of iron, tea, coffee, chocolate, dairy products and foods that are high in fiber content. Vitamin C can help increase iron absorption. If can't get enough, body will begin to deplete its iron stores. Decrease in ferritin level and ferritin saturation levels - impaired erythropoietis (microcytic, hypochromic) • Most often due to blood loss • Most commonly effects women of reproductive age and older adults

Megaloblastic Anemias: Management

• Patients with significant symptoms require RBC transfusions • Vitamin B12 deficiency due to absence of intrinsic factor: ◦ 1000 μg of cyanocobalamin or hydroxocobalamin IM every week x 8 weeks, then monthly for life. ◦ Anemia should resolve in 3-4 weeks • Folate deficiency: ◦ Folic acid 1mg PO qd ◦ Treat until underlying cause is corrected and/or normal Hgb level (4-6 weeks) ◦ Patients with inadequate diet may require lifetime regimen (sickle cell)

Iron Deficiency Anemia: Special considerations

• Pregnancy: ◦ Pregnancy places a greater demand on Fe stores ◦ If Fe deficiency is suspected pay attention to the serum ferritin level • Older Adults: ◦ If iron deficiency anemia is suspected screen for GI cancers (even in absence of negative occult blood test) ◦ At risk for anemia-related complications (e.g., cardiovascular events, falls, etc) ◦ Important to focus on the ferritin

Iron Deficiency Anemia clinical manifestations

• Weakness • Fatigue • Pallor • Decreased exercise tolerance • Tachycardia • Dyspnea • Headache • Dizziness or lightheadedness • Smooth, sore tongue* (*means most common) • Brittle and ridged nails* • Angular cheilitis* (fissures in corners of mouth) • Pica* (unusual craving for non-nutritive substance s - ice, dirt, starch)

Iron Deficiency Anemia diagnostic Profile

• decreased Ferritin (earliest change reflecting depletion of Fe stores) • decreased Fe • increased TIBC • decreased Hgb • CBC: • decreased Hct • decreased MCV (< 80 µm3) • decreased MCH • decreased MCHC

Megaloblastic Anemias: Diagnostic Profile

• decreased Hgb • decreased Hct • increased MCV (> 100 µm3) • increased MCH • MCHC normal • decreased reticulocyte count decreased vitamin B12 level • Positive intrinsic factor antibody test • decreased folic acid (folate) level • Leukopenia or thrombocytopenia

Other Hypoproliferative Anemia

•Anemia in renal disease ◦ Erythropoietin deficiency ◦ Normocytic •Anemia of chronic disease ◦ Associated with diseases of inflammation, infection, and malignancy ◦ Normocytic, normochromic •Aplastic anemia ◦ Due to decrease in or damage to bone marrow stem cells ◦ Significant anemia, neutropenia, and thrombocytopenia