Rickets--not only the "English disease".

Nutritional rickets in infancy and childhood due to vitamin D deficiency continues to be a world-wide problem. Its occurrence is probably higher in many tropical and sub-tropical countries, despite abundant sunlight than in many more northerly latitudes, where its incidence is mainly limited to children of Asian origin and those with dark skins. Social and cultural customs including the adherence to a special, often vegetarian diet, the avoidance of sunlight together with increasing urbanisation, extended breast feeding and severe malnutrition are recognisable factors in the pathogenesis of rickets. Recent research has suggested that the regulation of vitamin D metabolism may be different in black children compared with those who have a fair skin. Supplementation of mothers in pregnancy and of children in infancy with vitamin D together with health education to promote a diet containing foods rich in vitamin D can ameliorate this preventable disease.