Iron deficiency is caused primarily by inadequate iron intake, blood loss, an inability to absorb iron properly, and increased iron requirements. Common causes include eating too little iron-rich food, heavy menstrual bleeding or pregnancy (which increase iron demand or loss), internal bleeding from conditions like ulcers or cancers, gastrointestinal disorders such as celiac disease that impair iron absorption, and genetic factors affecting iron metabolism. Chronic blood loss, poor diet, malabsorption, and elevated physiological needs especially during growth or pregnancy are major contributors to iron deficiency.
