Iron deficiency anemia

Epidemiology 
A.Most common cause of Microcytic Anemia 

II.Causes 
A.Premenopausal women 
1.Excessive menstrual flow: 2 mg/day iron lost 
2.Dietary Iron absorption: 1.5 - 1.8 mg/day iron gained 
3.Each Pregnancy: 500 to 1000 mg iron lost 
B.Males and Postmenopausal women 
1.Gastrointestinal blood Loss 
2.Colon Cancer until proven otherwise 

III.Symptoms and Signs 
A.See Anemia 
B.Pica: Insatiable craving for unusual items 
1.Laundry starch 
2.Clay 
3.Ice 

IV.Labs 
A.Complete Blood Count (CBC) 
1.Hemoglobin or Hematocrit indicating Anemia 
2.Mean Corpuscular Volume (MCV) 
a.Normocytic anemia 
i.Normocytic early in course of Anemia 
b.Microcytic Anemia 
i.Microcytosis follows Hemoglobin drop of 2 g/dl 
3.Red Cell Distribution Width (RDW) 
a.Precedes change in Mean Corpuscular Volume 
B.Iron Studies (in order of sensitivity) 
1.Serum Ferritin <12ug/dl 
a.Falls before other indices 
b.Most sensitive for iron deficiency Anemia 
c.Falsely elevated in Hepatitis 
2.Total Iron Binding Capacity (TIBC) rises 
3.Serum Iron 
a.Falls after Serum Ferritin 
b.Falls after Total Iron Binding Capacity (TIBC) 
4.Transferrin saturation decreases 
5.Serum Iron to Total Iron Binding Capacity <16% 
C.Reticulocyte Count or Reticulocyte Index 
1.Useful in categorization of Anemia type 
2.Does not assess degree of iron deficiency Anemia 
D.Images 
1.
Hematology and Oncology Anemia Iron
Deficiency

(Click image to enlarge)


2.
Hematology and Oncology Anemia Iron
Deficiency On Treatment

(Click image to enlarge)



V.Management 
A.Identify a source of blood loss 
1.Beware adult men with iron deficiency Anemia 
2.Beware postmenopausal women iron deficiency Anemia 
B.Iron Supplementation 
1.Typical adult dosing 
a.Ferrous Sulfate 325 mg PO tid 
2.Anticipated response 
a.Week 2: Reticulocytosis (<10%) 
b.Week 3: Increased Hemoglobin halfway to normal 
c.Week 8: Normal Hemoglobin 
3.Continue Ferrous Sulfate 325 mg PO qd for 4-6 months 
C.Evaluate failure to respond to Iron Supplementation 
1.Noncompliance 
2.Poor iron absorption due to concurrent medications 
a.Concurrent antacid use 
3.Continued excessive blood loss 
4.Consider Parenteral iron if true malabsorption 

Causes 
A.Iron Deficiency Anemia 
B.Thalassemia 
C.Sideroblastic Anemia 
D.Anemia of Chronic Disease 

II.Labs 
A.Complete Blood Count 
1.Hemoglobin or Hematocrit consistent with Anemia 
2.Mean Corpuscular Volume (MCV) <82 
B.Reticulocyte Index <1% (Reticulocytopenia) 
1.See Anemia for causes of Reticulocytosis 
C.Mean Corpuscular Volume to Red Blood Cell Count ratio 
1.Ratio <13: Thalassemia 
2.Ratio >13: Iron Deficiency Anemia, Hemoglobinopathy 

Dietery Iron

Background 
A.Typical iron adult intake: 15-18 g/day 
B.Typical iron absorption: 1.5 to 1.8 mg/day 

II.Indications 
A.Increased requirements in menstruating women 

III.Risks 
A.Excessive iron intake may result in Hemachromatosis 

IV.Sources 
A.Liver 
B.Red meats 
C.Apricots 
D.Peaches 
E.Prunes 
F.Apples 
G.Grapes 
H.Raisins 
I.Spinach 
J.Eggs 

MCV

Normal 
A.MCV: 76-100 um 

II.Calculations 
A.MCV = 10 x (Hematocrit / Red Blood Cell Count) 

III.Increased (Macrocytic: implies RBC Maturation defect) 
A.Vitamin B12 Deficiency 
B.Folic Acid Deficiency 
C.Alcohol Abuse 
D.Liver disease 
E.Marrow aplasia 
F.Myelofibrosis 
G.Reticulocytosis 
H.Hypothyroidism 

IV.Decreased (Microcytic: implies Abnormal Hgb Synthesis) 
A.Iron Deficiency Anemia 
B.Thalassemia 
C.Hemoglobinopathy 
D.Anemia of chonic disease 
E.Sideroblastic Anemia 
F.Chronic Renal Failure 
G.Lead Poisoning 

Ferritin

Mechanism 
A.Acute phase reactant 

II.Normal 
A.Range: 18-300 ng/ml 

III.Increased 
A.Inflammatory states 
B.Hyperthyroidism 
C.Liver disease (necrotic hepatocytes) 
D.Hodgkin's Lymphoma and Non-Hodgkin's Lymphome 
E.Leukemia 
F.Breast Cancer 
G.Neuroblastomas 
H.Hemochromatosis 
I.Iron Supplementation 

IV.Decreased 
A.Iron Deficiency Anemia 

Serum Iron

Measurement 
A.Measures Transferrin-associated ferric ion 
B.Related measures 
1.Total Iron Binding Capacity 
2.Percent Transferrin Saturation 

II.Normal 
A.Range: 50 - 175 ug/dl 

III.Elevated Serum Iron 
A.Hemochromatosis 
B.Hemolysis 
C.Hemolytic Anemia 
D.Hemosiderosis 
E.Hepatic necrosis 
F.Hepatitis 
G.Ineffective erythropoesis 
1.Vitamin B12 Deficiency 
H.Iron Poisoning or Iron Overdose 
I.Lead toxicity or Lead Poisoning 

IV.Decreased Serum Iron 
A.Chronic Gastrointestinal Blood loss 
B.Heavy Menstrual Bleeding 
C.Inadequate iron absorption 
D.Insufficient Dietary Iron 
E.Iron Deficiency Anemia 
F.Malabsorption 
G.Nephrotic Syndrome 
H.Third trimester of pregnancy 

Reticulocyte count

Normal 
A.Range: 0.5-1.5% 

II.Increased 
A.Hemolytic Anemia 
1.Sickle Cell Anemia 
2.Thalassemia major 
3.Autoimmune Hemolytic Anemia 
B.Hemorrhage 
C.Post-Anemia Treatment 
1.Folate Supplementation 
2.Iron Supplementation 
3.Vitamin B12 Supplementation 

III.Decreased 
A.Aplastic Anemia 
B.Marrow suppression 
1.Sepsis 
2.Chemotherapy or radiotherapy 
C.Disordered RBC maturation 
1.Iron Deficiency Anemia 
2.Megaloblastic Anemia 
3.Sideroblastic Anemia 
4.Anemia of Chronic Disease 
D.Blood transfusion 
E.Liver disease 

Iron supplement

Also See 
A.Dietary Iron 

II.Indications 
A.Iron Deficiency Anemia 

III.Preparations 
A.Ferrous Sulfate (FeSO4) 
1.Elemental Iron: 15 mg per 0.6 ml dropper 
2.Elemental Iron: 18 mg per 5 ml Syrup 
3.Elemental Iron: 65 mg per 325 mg tablet 
B.Ferrous Gluconate (Fergon) 
1.Elemental Iron: 30 mg per 300 mg tablet 
2.Elemental Iron: 30 mg per 300 mg/5 ml syrup 
C.Iron Dextran (Imferon): Parenteral iron 

IV.Dosing 
A.General Anemia management 
1.Ferrous sulfate 325 mg PO tid 
B.Postpartum Iron Deficiency Anemia 
1.Hemoglobin 7-9 
a.Ferrous sulfate 325 mg PO tid 
2.Hemoglobin 9-10 
a.Ferrous sulfate 325mg PO bid 
3.Hemoglobin >10 
a.Ferrous sulfate 325mg PO qd 
C.Pediatric Anemia 
1.Severe Pediatric Anemia 
a.Ferrous Sulfate 4-6 mg/kg/day PO tid 
2.Mild Pediatric Anemia or Prophylaxis 
a.Ferrous Sulfate 1-2 mg/kg/day PO qd-bid 

V.Precautions 
A.Do not use with antacids (decreases absorption) 

VI.Adverse Effects 
A.Gastrointestinal distress 
1.Ferrous iron causes mucosal irritation 
2.Start with once daily dosing and titrate to tid 
3.Tolerance is directly related to iron concentration 
a.Start with normal concentration elemental iron 
i.Decrease to lower concentrations as needed 
b.Lower elemental iron concentration better tolerated 
i.Ferrous gluconate 
ii.More expensive iron preparations 
4.Enteric coated Iron has decreased absorption 
B.Black stools 
C.Hemochromatosis 
1.Prolonged, excessive iron supplementation