Among adolescents, iron-deficiency anaemia is one of the most common diet-related deficiency diseases. Adolescents are particularly susceptible to iron deficiency anaemia in view of their increased blood volume and muscle mass during growth and development. This raises the need of iron for building up haemoglobin, the red pigment in blood that carries oxygen, and for the related protein myoglobin, in muscle. The increase in lean body mass (LBM), composed mainly of muscle, is more important in adolescent boys than in girls. In preadolescent years, LBM is about the same for both sexes. Once adolescence starts, however, the boy undergoes a more rapid accumulation of LBM for each additional kilogram of body weight gained during growth, ending up with a final LBM maximum value double that of the girl. Other factors contributing to elevated iron needs are increased body weight and the beginning of menstruation for girls. All these factors should be taken into account when assessing iron needs in this group of age.
One of the most important diet considerations during adolescence
is an increase in the intake of iron-rich foods such as lean meats and fish as
well as beans, dark green vegetables, nuts and iron-fortified cereals and other
grains. Iron from animal foods (known as haem iron) is much better absorbed than
iron from non-animal sources (non-haem iron). Adolescents
following vegetarian diets are therefore at an increased risk of
iron-deficiency. However, vitamin C (e.g. from citrus fruits) and animal
proteins (meat & fish) assist in the absorption of non-haem iron.
