Etiology

Both iron deficiency anemia (macrocytic anemia) and vitamin B12 deficiency anemia (macrocytic anemia) are associated with hypothyroidism [Starr2005, pg 112].

Differential Diagnosis

  • Check CBC
  • Copper deficiency or zinc excess
  • Iron deficiency (check ferritin)
  • Vitamin B12 deficiency
  • Vitamin B9 (folate or folic acid) deficiency
  • Poor bone marrow function
  • Abnormal red blood cell function (sickle cell anemia, thalassemia, etc)
  • Hemolytic anemia

Treatment

Be sure to identify the nutritional imbalance before taking copper, zinc, or iron supplements! Taking the wrong supplement can be harmful!

Hypotheses

One possible explanation for the association of anemia and hypothyroidism is that hypothyroidism lowers body temperature resulting in reduced activity of red bone marrow [Starr2005, pg 138].

References