See related article, pp 1026–1032 Salt (sodium chloride) is an essential nutrient whose main role is to preserve the extracellular volume and hence contribute to the maintenance of an adequate circulatory volume. The crucial role of salt in maintaining volume is underscored by the fact that our kidneys have evolved over millions of years to become exquisitely efficient in prioritizing sodium conservation over all of the many regulatory functions of the kidney. This capability of our kidneys to retain salt was particularly important in ancient times when the availability of salt was scarce. However, as time passed, salt production increased and it became readily available to the general population. Eventually, the use of salt extended beyond food seasoning to food preservation. This led to remarkable increases in sodium consumption in most regions around the world; the exception being certain more primeval societies. There is abundant epidemiological evidence linking sodium intake to high blood pressure. Societies with a high salt intake tend to have a significantly higher rate of age-related increase in blood pressure, whereas those with low sodium intake, such as the Yanomamo Indians of northern Brazil who have intakes of <3 g/d, are associated with lower age-related blood pressure elevations.1 These trends are not just in adults. Studies in the United States have demonstrated that higher salt intake in children and adolescents is positively correlated with high systolic blood pressures and an elevated risk of prehypertension/hypertension.2 Indeed, such a notion aptly fits Guyton’s hypothesis,3 in that blood pressure goes up to achieve sodium balance through increased natriuresis. Although this increased natriuresis restores sodium …