Phytochemicals, prominent for their antioxidant and anticancer activities, differ in their chemical properties. These differences may affect bioavailability and distribution of each within the body in which they may act as prooxidants. The use of dietary supplements is growing among children. In higher concentrations, a risk of toxicity may exist. Maternal nutrition is important for fetal development and during lactation, breast feeding periods. Children are more sensitive than adults. Compounds, doses of which may be tolerated by adults may not be readily overcome by infants. Vitamin A supplements increase the risk of mother-to-child transmission of HIV. Trans-fatty acids in milk, a basic nutrient during childhood, which is affected by even cow's diet, are potential atherosclerosis progression factors and risk factors for obesity, a major health problem among children. Glycoalkaloids, aflatoxins, acrylamid are threatening compounds found in snacks. Regular mass administration of foods, or supplements should be done prudently during childhood. (c) 2005 Elsevier Ltd. All rights reserved.