Iron deficiency remains a problem in developing countries as well as in industrial nations. The prevalence of iron deficiency in children under 5 years of age is identical in Europe and the USA, and is in the order of 7 to 9% on average with an anaemia prevalence of 2.3%. The major cause is dietary deficiency, particularly in premature babies, infants, teenagers, and children in unstable situations. It is important to prevent the development of anaemia, especially in infants, due to its morbid consequences particularly with respect to development. Screening and simple preventative measures (iron supplements and dietary advice) need to be systematically set up, particularly in at-risk populations, and are detailed in the present article.