Diet plays a major role in iron binding capacity. Red meat, poultry, fish, beans, lentils, and dark leafy greens provide iron. Vitamin C from citrus fruits, peppers, and tomatoes helps your body absorb iron better. Tea, coffee, and calcium supplements can reduce iron absorption when consumed with meals. Heavy menstrual periods, pregnancy, blood donation, and gastrointestinal bleeding all deplete iron stores. Vegetarian and vegan diets require careful planning to meet iron needs from plant sources.
Chronic inflammation from infections, autoimmune conditions, or ongoing illness can lower TIBC independent of your actual iron levels. Liver disease reduces the liver's ability to produce transferrin, which lowers TIBC. Certain genetic conditions like hemochromatosis cause excessive iron absorption. Medications including proton pump inhibitors can reduce iron absorption over time. Celiac disease, Crohn's disease, and other gut conditions impair nutrient uptake. Understanding these factors helps you and your doctor identify the root cause of abnormal results.