Small differences in nitrate intake with the drinking water are not reflected in nitrate contents of saliva and urine of test persons. A correlation of nitrate concentration in body fluids and cancer incidence can be expected hardly. Inflammatory diseases of the gut are frequently accompanied by enhanced endogenous nitrate synthesis and have an essential influence on total nitrate load of the human organism. Nitrate contents in saliva and/or urine are not general indicators of inflammatory processes. As the role of the nitrate ion in humans is not yet understood, the claim remains for a nitrate intake being as low as possible.