| Transferrin saturation, ferritin, serum iron |
| Suspected etiologies |
| Iron deficiency |
| Remarks |
| Ferritin may be artificially elevated in chronic inflammatory states; transferrin saturation may be low in patients with cachexia |
| Fecal occult blood; upper and lower endoscopy |
| Suspected etiologies |
| GI-related blood loss |
| Remarks |
| Referral to gastroenterology may be required |
| TSH |
| Suspected etiologies |
| Thyroid related disorders |
| Peripheral smear, reticulocyte Multiple count / index, bone marrowbiopsy |
| Suspected etiologies |
| Multiple |
| B12 / folate |
| Suspected etiologies |
| Nutritional deficiency |
| Remarks |
| Uncommon in Canada |
| Hemoglobin electrophoresis |
| Suspected etiologies |
| Thalassemia; sickle cell disease |
| Remarks |
| Target testing to those in high prevalence population |
| Serum and urine protein electrophoresis |
| Suspected etiologies |
| Multiple myeloma, amyloidosis and other protein disorders |