Nutrient interaction effects relationships

Reports of lead-nutrient interactions in experimental animals have generally described such relationships in terms of a single nutrient, using relative absorption or tissue retention in the animal to index the effect. Most of the data are concerned with the impact of dietary levels of calcium, iron, phosphorus, and vitamin D. These interaction studies are summarized in Table 2-12. 

It is reasonable to assume the effect of plant roots and tops on the soil would be the same. However, this is not the case. Plant roots profoundly affect the chemical characteristics of soil. Because they are in intimate contact with the soil, roots are constantly extracting nutrients and water from the soil and exuding materials into it. The intimate relationship, which includes physical, microbiological, biochemical, bioorganic, and chemical interactions between roots and soil, is illustrated in Figure 4.3. 

It has been characteristic of nutrition studies to use one nutrient alteration experimental design to investigate one possible effect. However, in order to elucidate dietary relationships with pathological conditions, it may be necessary to use interaction-type studies. Therefore, the overall objective of the research conducted in our laboratories was to investigate the effect of dietary fat-manganese interactions on cholesterol synthesis. 

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