Accurate assessment of the quantitative significance of different sources of salt in the diet

A metabolic study was conducted to assess the validity of using lithium tagged salt as a technique for monitoring the sources of salt in the diet. Discretionary sources, table and cooking salt, were separately labelled and studied, the table salt being available ad libitum whereas cooking salt intakes were controlled. The study showed that lithium excretion in the urine did provide an accurate measure of the amount of the labelled salt ingested. Subsequent analysis suggest that Li is not excreted readily in sweat or faeces so it can be used on its own to ensure the completeness of a series of 24h urines. Latin American studies on salt sources in the diet are needed as a base for programmes of primary prevention of hypertension.