Nutrition-related Anemias

Overview

• Definition: Anemias caused by deficiencies in nutrients necessary for blood production
• Most common types:
  • Iron deficiency anemia (IDA)
  • Vitamin B12 deficiency anemia
  • Folate deficiency anemia

Types of Nutritional Anemias

1. Iron Deficiency Anemia (IDA)

   • Most frequently observed nutritional anemia
   • Essential for hemoglobin production
   • Iron cannot be excreted efficiently; body iron balance crucial

2. Vitamin B12 Deficiency Anemia

   • Results from insufficient dietary B12 or absorption issues
   • Often seen in individuals with dietary restrictions, gastrointestinal issues
   • Critical for DNA synthesis, neurological functionality
   • Sources: Animal products (liver, meat, eggs, dairy)

3. Folate Deficiency Anemia

   • Caused by inadequate dietary intake or increased need/demand
   • Important for DNA synthesis and cell division
   • Sources: Leafy greens (spinach, broccoli), fruits, meats (liver)

Iron Metabolism and Erythropoiesis

• Erythropoiesis Process: Development stages from stem cells to mature erythrocytes
  • Key stages: Proerythroblast, Early erythroblast, Late erythroblast, Reticulocyte, Erythrocyte
  • Takes about 5-7 days
• Iron Absorption
  • Dietary iron absorbed in the duodenum and upper jejunum
  • Iron stored in body as ferritin and hemosiderin in liver, spleen, and bone marrow
  • Regulated by hepcidin from the liver to control iron release into plasma

Critical Elements for Erythropoiesis

• Iron
• Vitamin B12
• Folate
• Ascorbic Acid (Vitamin C)
• Pyridoxine (Vitamin B6)
• Amino acids

Pathophysiology and Regulation

• Hemoglobin Formation
  • Consists of heme (iron-containing) and globin (protein chains)
  • Iron deficiency impairs hemoglobin production, leading to anemia
• Hepcidin Regulation
  • Produced by the liver; regulates iron egress from enterocytes to plasma
  • High hepcidin levels block iron release, leading to iron sequestration and reduced serum iron
  • Anemia and hypoxia reduce hepcidin, enhancing iron absorption
• Vitamin B12 and folate
  • Required for DNA synthesis, affecting rapidly-dividing hematopoietic cells
  • Carry out critical roles in methylation and DNA repair processes

Laboratory Findings and Diagnosis

• Iron Deficiency Anemia
  • Low serum ferritin
  • Low serum iron
  • Elevated total iron-binding capacity (TIBC)
  • Increased transferrin receptors
  • Presence of microcytic, hypochromic cells in blood smear
• Vitamin B12 and Folate Deficiency Anemia
  • Macrocytic anemia (MCV>100)
  • Hypersegmented neutrophils
  • Elevated serum homocysteine
  • Elevated methylmalonic acid (Vitamin B12 deficiency)

Clinical Features and Symptoms

1. Iron Deficiency Anemia
   • Fatigue, pallor, dyspnea, tachycardia
   • Specific: Pica, restless legs syndrome, koilonychia
2. Vitamin B12 and Folate Deficiency Anemia
   • Fatigue, pallor, glossitis, jaundice
   • B12-specific: Neurological issues (peripheral neuropathy, ataxia, cognitive disturbances)
   • Folate-specific: No neurological symptoms

Treatment and Management

• Iron Deficiency Anemia
  • Iron supplementation (200 mg elemental iron/day)
  • Correction of underlying cause (e.g., bleeding, dietary changes)
• Vitamin B12 Deficiency Anemia
  • Vitamin B12 injections (1000 µg IM daily for 10 days, then monthly)
  • Monitor neurological symptoms
• Folate Deficiency Anemia
  • Folate supplementation (1-5 mg daily)
  • Dietary modifications to increase intake of folate-rich foods

Summary

• Nutritional anemias are often preventable and treatable with proper dietary adjustments and supplementation.
• Identifying and treating the underlying causes is crucial for effective management.
• Regular monitoring and follow-up are essential to ensure treatment efficacy and prevent recurrence.