in high-Fe, low-pH and certain leached soils, and hence is often of limited availability to plants. Science of The Total Environment, Vol. Food Reviews International, Vol. Consequently, it is often supplied by plants to animals and human consumers at levels too low for optimum health. Faquin, Valdemar Guilherme, Luiz.G. Before recommending large-scale fortification of the food supply with Se, it will be necessary to await the results of current intervention studies with Se on cancer, HIV and aids, and asthma.