The circulation of nitrogen in nature is a prerequisite for life on earth. In the nitrogen cycle
atmospheric nitrogen is fixated by bacteria into forms that can be utilized by plants and
mammals. Nitrate and nitrite are obligate intermediates in this cycle, and for more than half a
century these anions have interested nutritional scientists, mostly in relation to cancer,
because of their ability to form nitrosamines. However, after the discovery of mammalian
endogenous nitric oxide (NO) generation and later that its oxidation products nitrate and …