Chloride is an essential mineral for humans and other animals that occurs primarily in body fluids. A small percentage of about 15% of chloride in the body is located inside cells, with the highest amounts in red blood cells.  Chloride is also present in very small amounts in bones. On average, an adult human body contains approximately 115 grams of chloride, making up about 0.15 percent of total body weight.  As a major electrolyte mineral of your body, chloride performs many roles. Without chloride, your body would be unable to maintain fluids in blood vessels, conduct nerve transmissions, move muscles, or maintain proper kidney function.

Chloride is a negatively charged ion in your blood, where it represents 70 percent of your body’s total negative ion content. As the primary negatively charged ion in your body, chloride serves as one of the main electrolytes. Along with potassium and sodium, chloride helps conduct electrical impulses when dissolved in bodily fluids. Potassium and sodium become positive ions as they lose an electron when dissolved, and chloride becomes a negative ion as it gains an electron when dissolved. A positive ion is always accompanied by a negative ion. That’s why there’s a close relationship between sodium, potassium, and chloride. Electrolytes are distributed throughout all your body fluids including your blood, lymph, and the fluid inside and outside cells. The negative charge of chloride balances against the positive charges of sodium and potassium ions in order to maintain the balance of particles in your blood.

In addition to its functions as an electrolyte, chloride combines with hydrogen in your stomach to make hydrochloric acid, a powerful gastric fluid responsible for breaking down proteins, absorbing other metallic minerals, and activating intrinsic factor, which, in turn, absorbs vitamin B12. Chloride is specially transported into your stomach, in exchange for another negatively charged electrolyte, bicarbonate, in order to maintain electrical neutrality across the stomach membrane. After your stomach uses chloride for hydrochloric acid, some of it is reabsorbed by your intestine back into your bloodstream, where it is required to maintain the fluid volume.

Your red blood cells and your blood plasma constantly exchange chloride and bicarbonate to regulate pH balance and transport carbon dioxide, a waste product of respiration, from your body. Along with sodium and potassium, chloride works in your nervous system to help transport electrical impulses throughout your body, as negatively charged chloride moving into your cells causes nervous electrical potential.

Deficiencies of chloride are rare. Low chloride (hypochloremia) may result from water overload and excessive loss of sodium, such as heavy sweating during endurance exercise, and in cases of prolonged vomiting and diarrhea. Less commonly, it occurs from wasting conditions, and in cases of burns over large parts of the body. However, chloride deficiency does occur, it may result in a life-threatening condition known as alkalosis, in which the blood becomes overly alkaline. Your body works hard to maintain a constant balance between alkalinity and acidity. Symptoms of alkalosis include muscle weakness, loss of appetite, irritability, dehydration, and lethargy. When infants are fed chloride-deficient formula, many experienced failure to thrive, anorexia, and weakness in their first year of life.

You can get too much chloride if you eat too much salt and potassium chloride; however, the adverse health effects of such diets are attributed to high sodium and potassium levels, two other electrolyte minerals to which chloride is often attached. Excess chloride is normally excreted in the urine, sweat, and bowels. In fact, excess urinary excretion of chloride occurs in high-salt diets. Chloride toxicity is rare in humans except in the case of impaired sodium chloride metabolism, for example, in congestive heart failure. Another situation in which increased blood levels of chloride are seen include diseases of improper waste elimination, which occurs in kidney diseases. Healthy people can tolerate large quantities of chloride, provided that they drink enough fresh water.  Excessive intakes of chloride can occur in people with compromised health in addition to an unhealthy diet.

Chloride is a by-product of the reaction between chlorine and an electrolyte, such as potassium, magnesium, or sodium, which are elements that are essential for human metabolism. Elemental chlorine is a dangerous gas. Because it is so reactive, it does not exist in its free elemental state in nature, although it is common in compounds with other elements. One of the most common chlorine compounds is common table salt, sodium chloride. Chloride salts are essential for sustaining human metabolism and have none of the toxic effects of isolated chlorine gas. Your body can safely use chloride without negative health effects.The negative health effects that have been associated with diets high in chloride, such as fluid retention and high blood pressure, are mainly attributable to the accompanying sodium and potassium.

Your body rapidly excretes chloride, so it’s essential that you replace it on a daily basis to maintain a healthy metabolism. Healthy adults should consume 1.5 grams of sodium and 2.3 grams of chloride each day (3.8 grams of salt) to replace the amount lost daily on average through sweat and to achieve a diet that provides sufficient amounts of other essential nutrients. Chloride occurs naturally in foods at levels normally less than 0.36 milligrams per gram of food. The average intake of chloride on a salt-free diet is approximately 100 milligrams per day. The most common dietary source is table salt, which is made up of sodium and chloride ions. Healthier sources of chloride include kelp, olives, rye, tomatoes, lettuce, and celery, but it doesn’t occur in these foods in large enough amounts to supply the needs of an active adult. Active adults who eat a diet devoid of salt, along with people who are ill with vomiting or diarrhea may need supplemental additional chloride.