Chloride

Description

Chloride constitutes approximately 0.15% of human body weight. It is primarily found in cerebrospinal fluid and gastrointestinal secretions. Chloride is present in small amounts within bone. It is the major anion in plasma and interstitial fluid, where it aids in the maintenance of osmotic pressure and electrolytic balance.

Chloride is essential for the production of hydrochloric acid, which is secreted from the parietal cells of the stomach, and vital in maintaining the proper acidic environment for pepsin. Chloride is essential, as are sulfur and phosphorus, in maintaining the acid/base balance of the body fluids. It is essential in buffering the acid/base fluctuations which occur during carbon dioxide uptake and release in red blood cells. It is also influential in the conservation of potassium, which is inefficiently resorbed by the body.

Chloride is absorbed primarily in the intestine and secreted through urine, sweat, vomit and diarrhea.

Method of Action

Chloride exists primarily in sodium chloride (table salt). It is complexed with sodium in extracellular fluids, and with potassium in intercellular fluids.

Chloride is an integral part of hydrochloric acid which is secreted from parietal cells in the stomach lining for the purpose of establishing a favorable pH in which pepsin can function.

Chloride is membrane-permeable. It therefore has the ability to pass freely in and out of the red blood cells, allowing the maintenance of osmotic equilibrium despite changing bicarbonate levels in the plasma and red blood cells.

Properties & Uses

Chloride and potassium supplements are effective in treating metabolic alkalosis, which is caused by excessive potassium and chloride loss.

Sodium chloride (table salt) is useful in a variety of therapeutic applications. For example, a 0.9% sodium chloride/water solution has been found effective in rehydration treatment of excessive dehydration. Sodium chloride supplementation is used to minimize decreases in blood volumes experienced by fasting patients and it is advised for persons who have experienced excessive perspiration, to reestablish lost electrolytes.

A decrease in sodium chloride consumption has been noted as beneficial for persons suffering from congestive heart failure or hypertension.

Consequence of Deficiency

The use of diuretics, as well as excessive diarrhea and/or vomiting, can deplete the body of chloride ions. This results in metabolic alkalosis, a condition which leads to an elevated blood pH.

Symptoms of metabolic alkylosis include decreased ventilation, a urinary pH change from alkali to acidic ranges, and excessive excretion of potassium. Hypokalemic metabolic alkalosis is an acute deficiency in potassium, accompanied by an elevation of blood and tissue pH. This disorder affects muscle function, resulting in difficult respiration and swallowing and, on occasion, death.

Chloride deficiency is most notably conspicuous in infants fed exclusively on chloride-deficient formulae. This deficiency is characterized by a loss of appetite, lethargy, muscle weakness, and severe hypokalemic metabolic alkalosis.

Toxicity Factors

Chloride has no known toxicity factor at this time, since excess chloride is excreted from the body. A daily intake of more than 14 to 28 grams of salt is considered excessive.

Recommended Dietary Allowance

No specific statement of human requirement for chloride has been established. Because chloride's primary dietary source is from sodium in table salt, an adequate sodium intake insures an ample chloride supply.

Food Sources

Beef liver	Bread
Cheese	Chicken liver
Clams	Dried beef
Egg	Frankfurters
Ham	Lamb liver
Lobster	Milk
Olives (green)	Oysters
Peanut butter	Pork
Salmon (canned)	Sardines
Sauerkraut	Sausage
Scallops	Shrimp
Table salt	Tomato juice
Turkey liver	Veal liver
Vegetables (canned)

References

Czanarin, Doris, M. 1984. Minerals - Food, Nutrition and Diet Therapy M.V. Krause and L.K. Mahan. W.B. Saunders Co, Phila.

Goodhart, Robert S. & Maurice E. Shills. Modern Nutrition In Health And Disease. 6th edition. Philadelphia: Lea and Febiger, 1973.

Guthrie, Helen A. Introductory Nutrition. 5th edition. St. Louis: C.V. Mosby Co., 1971.

Kirschmann, John D. Nutrition Almanac: Nutrition Search Inc. New York: McGraw-Hill, 1975.

Krause, M.V. & L.K. Mahan. 1979. Food, Nutrition and Diet Therapy. 6th ed. W.B. Saunders Company, Philadelphia. 963 pp.

Mitchell, G.A.G. & E. L. Patterson, Basic Anatomy. 2nd edition. Edinburgh: E and S Livingstone Ltd., 1967.

Orten, J.M. & Otto W. Neuhaus. 1982. Human Biochemistry. Mosby Co. St. Louis. 984.

Walji, Hasnain. 1992. The Vitamin Guide-Essential Nutrients for Healthy Living, Element Books, Dorset .U.K.

Walji, Hasnain. 1994. Vitamins, Minerals and Dietary Supplements - A definitive Guide to Healthy Eating . Hodder Headline Plc. London.

Williams, Sue Rodwell. Nutrition And Diet Therapy. 5th edition. St Louis: Times Mirror Mosby, 1985.

Wilson, Eva D., et al. Principles Of Nutrition. 4th edition. New York: John Wiley & Sons, 1979.

Windholz, Martha, Susan Budavani, et. al. 1976. The Merck Indes. Merck and Co., Inc. New Jersey.