Final answer:
Iron deficiency can result from insufficient dietary iron, poor absorption, chronic bleeding, increased demand during growth or pregnancy, and certain diseases that affect nutrient absorption like celiac or Crohn's disease.
Step-by-step explanation:
The causes of iron deficiency are varied and can include dietary deficiency, such as a lack of iron in the diet or consumption of foods high in phytates that inhibit iron absorption. Additionally, conditions that impair absorption of iron, like malabsorptive syndromes, can lead to iron deficiency. Factors such as chronic blood loss, whether from menstruation, slow bleeding due to gastrointestinal conditions, or other health issues, can also contribute. During periods of rapid growth, pregnancy, or recovery from blood loss, the body's demand for iron increases, which can outpace intake.
Other specific causes include dietary choices, where vegans and vegetarians may not consume adequate heme iron, thereby increasing their risk of deficiency. Furthermore, certain diseases such as celiac disease can cause malabsorption of iron, while others like Crohn's disease may require surgeries that affect the gastrointestinal tract and hence iron absorption. Lastly, ensuring adequate intake of nutrients like vitamin B12 and folate is crucial since their deficiency can also lead to anemia.