Iron deficiency can occur as a result of malnutrition, malabsorption of iron, or diseases and conditions that deplete iron either directly or indirectly, such as peptic ulcers, inflammatory bowel disease, colorectal cancer, major surgery or excessive menstrual bleeding. According to the World Health Organization (WHO), iron deficiency is the most common and widespread nutritional disorder of all. Some two billion people in total, or more than 30% of the global population, are anemic – many of them due to iron deficiency.
In developing countries, where an estimated 50% of pregnant woman and 40% of preschool children are anemic, iron deficiency is often exacerbated by worm infections, malaria and other infectious diseases such as tuberculosis, HIV/AIDS or schistosomiasis. The true scale of the problem is hidden behind health statistics such as death rates, incidents of maternal hemorrhage or poor performance in schools.
Ultimately, though, iron deficiency is a global public-health issue, one of epidemic proportions. For example, lack of iron is the only nutrient deficiency with significant prevalence in industrialized countries.