ABSTRACT
Much of the experimental work conducted with vitamin deficiency dis ease has focused on the deficiency of a single vitamin, with all other vitamins and nutrients held constant. While this experimental approach is essential to our understanding of the function of individual vitamins, it does not accurately reflect nutrient deficiency profiles in the real world, where vitamin deficiencies generally do not occur as single entities, but rather as multiple deficiencies. The classic example is that of pellagra, where deficiencies of niacin and tryptophan are usually accompanied by deficiencies of vitamin B6 and riboflavin (Säuberlich, 1980).
