Chloride

What is chloride?

Chloride is a negatively charged ion of the chemical element chlorine. It is an essential nutrient to human life and health.

The chemical symbol for chloride is Cl^–.

Chloride Functions

Chloride helps to keep the amount of the fluids inside and outside of the cells in balance, and helps to maintain the blood volume, pressure and pH. It is also needed for the production of hydrochloric acid (HCl) in the stomach.

Foods High in Chloride

The main source of chloride for a human are table salt, which is sodium chloride (NaCl), and a salt substitute potassium chloride (KCl). Excessive chloride is excreted (usually together with excessive sodium) through the kidneys into the urine.

Hypochloremic Alkalosis

A low level of chloride in the blood associated with a high blood pH is called hypochloremic alkalosis. This rare condition may result from a loss of chloride due to recurrent vomiting, diarrhea or suction of stomach contents, excessive sweating, cystic fibrosis (high sweat salt content), genetic kidney disorders, overuse of diuretics or laxatives, blood transfusion, bicarbonate infusion, hyperparathyroidism, or vitamin D toxicity ^[1].

Symptoms may include fatigue and loss of appetite; chronic hypochloremic alkalosis in children may result in a failure to thrive ^[2].

Hyperchloremic Acidosis

A high level of chloride in the blood associated with a low blood pH is called hyperchloremic acidosis. It may result from bicarbonate anion (HCO3-) loss and compensatory chloride anion retention by the kidneys. This may occur in severe diarrhea, bowel, biliary or pancreatic disorders, drugs overdose (cholestyramine, calcium chloride, magnesium sulfate) ^[3].

The main symptom is difficulty breathing during exertion. In chronic acidosis, osteoporosis may develop.

Other causes of hyperchloremia include kidney disorders and an overdose of infusions containing sodium chloride. Intake of more than 15 g of salt (sodium chloride) per day may result in a mild and temporary body swelling, nausea, vomiting or diarrhea, but not likely in an overt chloride toxicity. If you are healthy and have a regular diet containing at least 0.5 g and no more than 15 g of salt per day, you do not need to worry about chloride deficiency or toxicity.

When alkalosis or acidosis are suspected, the levels of chloride in the blood and urine can be checked together with sodium, bicarbonate and potassium levels (as part of the ‘metabolic’ or ‘electrolyte panel’).