GLOSSARY

Sodium Balance compares entry and loss over a defined period, rather than equating a balance result with one blood concentration.

Renal sodium reabsorption and excretion work with hormonal signals and water regulation to influence volume and pressure. Sweat and diarrhea provide other loss routes, while heat acclimation can alter sweat composition. Low urinary excretion does not always indicate low intake: the body may retain sodium in response to reduced volume. Interpret the time period and fluid context together.

Sodium supports extracellular fluid volume, nerve signaling and intestinal uptake of some substances. Dietary sodium arrives in salts and additives, not as free metal. Its role in muscle function does not mean salt is needed before every workout. Usual food intake, actual losses and environmental conditions determine whether the plan needs adjustment, rather than the nutrient's physiological importance alone.

Loss is not confined to sweat: urine, stool, secretions and sometimes bleeding contribute. Different elements use these routes in different proportions, so sweat volume cannot predict every mineral loss. In athletes, consider persistent changes, gastrointestinal illness, medicines and bleeding separately. Replacing one nutrient does not necessarily address the reason for its loss or establish that the rest of the mineral profile is adequate.