Consumption of beetroot juice (BRJ) supplements has become popular among athletes because beets tend to be rich in nitrate (NO3−), which can enhance exercise performance by increasing nitric oxide production. The NO3− content of beets can vary significantly, however, making it difficult to know how much NO3− any product actually contains. Samples from 45 different lots of 24 different BRJ products from 21 different companies were therefore analyzed for NO3− (and nitrite [NO2−]) conc...