Chlorine, in the form of chloride ion, is the most abundant component of sea salt, and is used for many things in the human body. Chloride ions are the major anion electrolytes within the extracellular fluid that surrounds every cell in the body. These ions in the extracellular fluid are important for regulating the pH and electrolyte concentration of the body. It is also an essential component of hydrochloric stomach acid. Chloride deficiencies can cause dehydration, fluid loss, and fatigue.