This document discusses nutritional anemias, including iron deficiency anemia and megaloblastic anemia caused by vitamin B12 or folic acid deficiency. It covers the metabolism and absorption of iron and these vitamins, causes of deficiency including diet and malabsorption, clinical manifestations of deficiency anemias, diagnostic tests, and management approaches including oral and parental supplementation.

1. Nutritional anemia
Iron deficiency- microcytic
&
Vitamin B12/FA- macrocytic

2. Iron metabolism
 Iron exists in body as-
 Hemoglobin- ~2000 mg
 Ferritin- M ~1000 mg, F ~0-500 mg in RE system
 Hemosiderin
 Transported- bound to transferrin
 Rich sources- liver, legumes, meat
 Absorption-
 Mostly in proximal small intestine in ferrous form
(acidic pH in stomach converts ferricferrous iron)
 ~10% of dietary iron is absorbed i.e. ~1 mg/day
 Excretion- ~1mg/day in feces

3. Deficiency- causes
 Dietary- in poor, infants, adolescents
 Blood loss
 Menstruation
 Pregnancy
 GIT- NSAIDs, hookworm, hemorrhoids,
angiodysplasia, diverticuli
 Hemoptysis
 Hematuria
 Impaired absorption- gastric resection

4. Manifestation
 Iron deficiency causes anemia
 History to identify cause/source of blood loss
 Clinical-
 Fatigue, palpitation, pica
 Pallor, tachycardia, systolic flow murmur
 Koilonychia- spoon-shaped nails
 Laboratory-
 Low serum ferritin & reduced BM iron
 Microcytosis with aniso/poikilocytosis, hypochromia
 Anemia- low Hb/Hct with low MCV & increased RDW

5. Iron studies/panel
 Includes serum iron, transferrin, TIBC,
transferrin saturation & ferritin
 Interpretation-
 Iron- low in Fe deficiency anemia &
anemia of chronic disease
 Transferrin/TIBC- increased in Fe deficiency &
pregnancy/OCP use
 Transferrin saturation- low in Fe deficiency,
anemia of chronic disease & pregnancy/OCP use
 Ferritin- low in Fe deficiency anemia

6. Management
 Determine & remove cause
 Oral iron-
 Plain ferrous salt (Ferrous sulfate)
 65 mg elemental iron- 1 cap.- TID between meals
 SE- dyspepsia, constipation/diarrhea, abdominal cramps
 Monitoring- reticulocyte count raised in 7 days,
nearly complete correction of anemia in 2 months
 Duration- ~6 months to replenish stores
 Parenteral iron- if impaired absorption
 Iron dextran, 2 ml (100 mg) IM OD
 Total dose- Hb. Deficit x weight in lbs. + 1000
 PRBC transfusion- if other organs compromised

7. Megaloblastic anemia
 Dyssynchronous nuclear & cytoplasmic
maturation in all 3 hematopoietic cell lines
 Caused by aberrant DNA synthesis,
due to vitamin B12 or folic acid deficiency
 Causes macrocytic anemia, with
megaloblasts (>5) lobed hypersegmented
neutrophils in bone marrow
 Can cause pancytopenia

8. Vitamin B12
 Function- works as an enzyme
 Deficiency leads to intracellular methionine deficiency that
blocks availability of reduced folate for DNA synthesis
 Further deficiency results in defective conversion of propionate
to succinyl CoA, causing defective myelin synthesis
 Source- bacteria & animal sources
 Absorption- in distal ileum, bound to IF
produced in stomach
 Average daily requirement- ~1-3 µg/day
 Store- ~2-5 mg in liver (x 3-4 years)

9. Deficiency
 Causes-
 Vegan diet
 Malabsorption- pernicious anemia, gastrectomy, ileal resection, Crohn’s
disease, blind loop syndrome, D.latum infestation
 Manifestation-
 Anemia, glossitis, mild icterus
 SACD- subacute combined degeneration of cord-
predominantly dorsal column sensory symptoms
 Dx-
 Serum cobalamin
 Plasma/urine methylmalonic acid
 Rx-
 Correct underlying cause, if possible
 Replacement- vitamin B12, IM for life

10. Folic acid
 Function-
 Deficiency impairs thymidine synthesis,
retarding DNA synthesis
 Source- green vegetables, yeast, liver
 Absorption- proximal jejunum
 Average daily requirement-
~100 µg/day
 Store- ~5 mg in liver (x 3-4 months)

11. Deficiency
 Causes-
 Reduced intake- alcoholics, malnourished
 Increased need- pregnancy, hemolytic anemia
 Malabsorption- tropical sprue, SI surgery/lymphoma
 Impaired utilization- methotrexate,
trimethoprim, pyrimethamine
 Manifestation- anemia, mild icterus
 Dx- serum/RBC folate levels
 Rx- oral FA, 1 mg/day