Iron Deficiency and Body Weight

Physiological Relationship Between Body Weight and Iron Stores

• Total body iron is calculated per kilogram of body weight, with men averaging 50 mg/kg and women 42 mg/kg, according to the Centers for Disease Control and Prevention 1, 2
• Men store approximately 1.0-1.4 g total body iron, women 0.2-0.4 g, as reported by the Centers for Disease Control and Prevention 3, 4, 5
• Low birthweight infants have the same ratio of iron to body weight as normal weight infants, but their absolute stored iron is proportionally lower, as noted by the Centers for Disease Control and Prevention 4, 6, 7

Clinical Implications for Iron Assessment

• Standard ferritin cutoffs must be adjusted upward in the presence of obesity-related inflammation, with ferritin up to 100 μg/L potentially representing iron deficiency, according to the European Crohn’s and Colitis Organisation and the European Society for Clinical Nutrition and Metabolism 8, 9
• Without inflammation, ferritin <30 μg/L indicates iron deficiency, whereas with inflammation, ferritin 30-100 μg/L suggests combined true iron deficiency and anemia of chronic disease, as recommended by the European Crohn’s and Colitis Organisation and the European Society for Clinical Nutrition and Metabolism 8, 9