Table 3.

Causes of iron deficiency or iron deficiency anemia

Gastrointestinal disorder with increased iron losses	Cancer/polyp: colon, stomach, esophagus, small bowel Peptic ulcer, esophagitis NSAID use Inflammatory bowel disease: ulcerative colitis, Crohn’s disease Intestinal parasites Vascular lesions: angiodysplasia, watermelon stomach Meckel’s diverticulum
Gastrointestinal disorders that reduce iron absorption	Celiac disease Bacterial overgrowth Whipple’s disease Lymphangiectasia Gastrectomy (partial and total) and gastric atrophy Gut resection or bypass
Urological and gynecological disorders	Menorrhagia Hematuria Chronic renal failure
Intravascular hemolysis myxomas	Prosthetic valves and cardiac Paroxysmal nocturnal hemoglobinuria Marathon runners Multiple blood donations
Deficient intake	Low socioeconomic class Vegetarian diets Dissociated diets Alcoholism Elderly patients High-risk ethnic groups
Medication that reduces gastric acid or iron affinity	Dietary factors Tannin Phytates in fiber Calcium in milk Tea Coffee
Increased requirements in various stages of life	Infants up to 3 years and adolescents Pregnant women Breastfeeding women Multiparous Post-partum

Abbreviation: NSAID, nonsteroidal anti-inflammatory drug.