Effect of a chemically defined diet on urinary excretion of minerals and aromatic compounds.

A diet of known composition, prepared from pure chemicals, was fed to a healthy man for five days. Urinary excretion of minerals, ultravioletabsorbing compounds, phenolic acids, indoles, and phenolic amines was determined by use of conventional techniques, high-resolution column chromatography, and thin-layer chromatography. The excretion of compounds during the period of the synthetic diet was compared with that when a self-selected diet was ingested. Institution of the synthetic diet caused a decrease in mineral excretion, and also caused the excretion of many aromatic compounds to decrease markedly. Several additional compounds could be attributed to the flavoring agent in the diet. We conclude that many compounds present in urine samples have a dietary origin primarily, and that it is necessary to feed diets of known composition before satisfactory metabolic studies may be undertaken.