Iron deficiency is the most common nutrient deficiency worldwide. The people most at risk for iron deficiency are:
- Females due to blood (and iron) loss through menstruation
- Pregnant women, as double the usual amount is required during pregnancy
- Infants and young children, due to poor intake
- Teenagers, as they require adequate iron for growth spurts but often have poor diets
- Vegetarians and vegans, as iron from plant sources is not as easily absorbed as from animal sources