In addition to already mentioned symptoms, the symptoms of lacking iron also include feeling weak and shortness of breath in already small efforts, brittle nails and hair. At the same time, the lack of iron causes dizziness, lightheadedness, faster heart rate and lack of appetite. The most frequent causes for a severe lack of iron and anemia are chronic losses of blood, and there also be a lack of iron in case of insufficient intake of nutrients or iron absorption disorders, e.g. celiac disease or other inflammatory bowel diseases. Lack of iron is particularly dangerous during pregnancy and early childhood, since it can cause complications from pregnancy and an impaired psychomotor and cognitive abilities of the child.

Lack of iron and anemia is also common in athletes. During intense and long physical activity, iron consumption increases drastically due to higher requirement for muscle supply with oxygen and loss of iron through perspiration. Female athletes, in particular, are at a higher risk of lacking iron due to the monthly loss of blood as a consequence of the menstrual cycle. It is estimated that 50% of female athletes lack in iron.

Almost 30% of women during their child-bearing period are anemic due to the loss of blood as a result of menstruations, whereas approximately 40% of pregnant women experience lack of iron. Already during pregnancy, in the first years after giving birth and even later, the organism needs to be sufficiently replenished with iron. An increased need for iron during pregnancy (30 mg/day) and during breastfeeding (20 mg/day) has to be taken into account when planning the diet of mothers. These intakes are hard to achieve with food only, this is why iron supplements should be added to the diet.