Iron deficiency is one of the most common nutritional problems, and occurs in a wide range of age groups.

There have been many recent opinions about iron, particularly in the infant's diet. There are no accurate Australian figures for the prevalence of iron deficiency in infancy, but a declining trend has been shown in the USA. In healthy infants iron deficiency is a preventable problem.

Bed wetting or nocturnal enuresis may be defined as 'persistent and frequent involuntary urination during sleep, beyond the age at which voluntary control is usually acquired'. This age is about 5 years.