# 9.2 Chloride

Chloride is one of the major minerals in the human body and helps fluid levels in the body remain balanced by working closely with both sodium and potassium. Chloride works by maintaining fluid levels on the outside of cells in the body. Chloride is also an important contributor to the making of hydrochloric acid, an important digestive fluid, and can be found in the lining of the stomach (Chloride Requirements and Dietary Sources n.d). Chloride is an essential nutrient that occurs primarily in blood fluids. It has many roles in our body, so it is important that we get the proper amount of chloride in our diets. Chloride comes from the element chlorine (Cl2), which can exist as a poisonous gas. When chlorine reacts with sodium, potassium, or hydrogen, it forms the negative ion chloride (Cl-). This anion functions as an electrolyte. Because it is an electrolyte, it plays an important role in the fluids throughout the body including lymph, blood, and the fluid found on the inside and the outside of cells (Chloride: The Forgotten Essential Mineral n.d). The Recommended Dietary Allowance (RDA), which is the amount of a vitamin or mineral that an individual should consume in one day, for chloride varies from person to person based on age, gender, illness, and pregnancies. Most people ages 9–50 years old should consume about 2.3 grams of chloride per day and that amount will decrease for individuals that are outside of that age range (Institute of Medicine n.d). People must consume an adequate amount of chloride each day to compensate for the loss of chloride that happens daily through sweating and other releases of body fluids. Although it is important to have chloride in the body, it is also important to not have too little or too much, as it can be harmful. One of the main ways a person may experience a deficiency of chloride in the body is if the body loses a lot of fluids, in which case a person may experience dehydration and the associated symptoms. Having too much chloride in the body, which is associated with consuming too much salt in the diet, can lead to increased blood pressure and can cause the buildup of fluids in people with preexisting conditions like congestive heart failure or kidney disease (Chloride in diet: MedlinePlus Medical Encyclopedia n.d).
Chloride in diet: MedlinePlus Medical Encyclopedia. (n.d.). Retrieved December 2, 2015, from https://www.nlm.nih.gov/medlineplus/ency/article/002417.htm
Chloride Requirements and Dietary Sources. (n.d.). Retrieved December 2, 2015, from http://nutrition.about.com/od/mineralglossary/g/chlorideglossary.htm
Chloride: The Forgotten Essential Mineral. (n.d.). Retrieved December 2, 2015, from http://www.traceminerals.com/research/chloride
Institute of Medicine. (n.d.). Retrieved December 2, 2015, from https://iom.nationalacademies.org/Reports/2004/Dietary-Reference-Intakes-Water-Potassium-Sodium-Chloride-and-Sulfate.aspx
Chloride. (2015, February 24). Retrieved December 1, 2015, from https://labtestsonline.org/understanding/analytes/chloride/tab/test/ Chloride in diet. (2013, February 18). Retrieved November 17, 2015 from https://www.nlm.nih.gov/medlineplus/ency/article002417.htm Whitney, E., & Rolfes, S. (2016). Water and the Major Minerals. In Understanding Nutrition (14th ed.). Stamford, CT: Cengage Learning.

## 9.1.1 Sources

Most people usually consume more chloride than needed, especially in America where there is an abundance of processed foods. Chloride is very easy to consume, as it is in most foods and can be added to any food as sodium chloride, which is table salt. However there are certain foods that contain more chloride than others, some of these are seaweed, celery, and olives (Chloride in diet: MedlinePlus Medical Encyclopedia n.d). In the air, Cl2 forms and is in fact poisonous (Whitney, 2013). Chloride is abundant in processed foods due to the influx of salt added to them. NaCl is the molecular name for table salt. Foods with a high content of chloride include seaweed, rye, tomatoes, lettuce, celery, and olives. Unhealthful sources of chloride include yeast extract, processed lunch meats, and cheese. Chloride can also bind with potassium to form a salt substitute (times).
Chloride can be found in many foods as part of salts such as sodium chloride. Chloride is especially prevalent in processed foods, which are known to have extra added salt. However, many vegetables such as tomatoes, lettuce, celery, seaweed, and olives also contain chloride. The chloride consumed through the diet is absorbed by the intestine, and excess is excreted in urine, sweat, or bowels. Chloride in diet. (2013, February 18). Retrieved November 17, 2015 from https://www.nlm.nih.gov/medlineplus/ency/article002417.htm

## 9.1.2 Functions

Chloride is considered an essential, major mineral of the body, requiring an intake of 2.3 grams per day. Being an essential nutrient, it is required for the body to function properly. Chloride has multiple important uses in the body. It is needed for fluid regulation and electrolyte balance. It is important for fluid regulation—if there is an excess of chloride ions in the blood, this leads to dehydration. It also helps to maintain decent blood pressure. Chloride can be found in the blood, being that it is the most abundant anion in the extracellular fluid. It can passively go into cells whenever needed, to interact with potassium. It is mostly ingested as table salt, paired with sodium. For this reason, it is easy to measure chloride levels in the blood as they are relatively the same as sodium levels. Chloride also helps the body maintain an acid-base balance from stomach acid, along with regulating cystic fibrosis transmembrane conducting regulators (CFTRs). If there are mutations or abnormalities in these regulators, cystic fibrosis can occur, along with major loss of water in the form of diarrhea, leading to an electrolyte imbalance in the body. Chloride also works in hydrochloric acid, a very strong acid and the main component in gastric juice. Its low pH allows for the breakdown of food—if it weren’t so acidic, this would not be possible and digestion would not occur as efficiently, if at all. Though this acid is beneficial for digestion, it can cause some problems with those prone to acid reflux or bulimia. This acid, if not treated properly with an antacid, can lead to wearing down of the esophagus or decaying of the teeth over time with frequent exposure.
The main function of chloride in the body is to maintain fluid balance. In humans, chloride makes up a large majority of the extracellular fluids (fluid outside of the cell). It is the major anion in the body, which also allows it to function as a principle electrolyte in our bodies as well. Chloride is very important for the electric potential difference across a cell’s membrane. Chloride is able to move passively across cell membranes bringing other nutrients with it. Outside the cell, chloride associates with sodium in order to maintain osmotic pressure of body fluids. Inside the cell chloride associates with potassium. Chloride also assists in the conduction of electrical impulses when paired with potassium or sodium. When dissolved, chloride becomes a negative ion while sodium and potassium become positive ions.
Chloride also plays a role in the stomach as the key digestive acid, hydrochloric acid (HCl). Hydrochloric acid maintains the acidity of the gastric juice and kills germs in our food. Hydrochloric acid lowers the pH of the stomach, making it more acidic, which then activates pepsinogen to pepsin. Pepsin is an important endopeptidase that breaks down proteins so they can be digested.
Chloride. (2015, February 24). Retrieved December 1, 2015, from https://labtestsonline.org/understanding/analytes/chloride/tab/test/ Chloride in diet. (2013, February 18). Retrieved November 17, 2015 from https://www.nlm.nih.gov/medlineplus/ency/article002417.htm Sodium and Chloride. (2012, February 25). Retrieved December 1, 2015, from http://www.nutri-facts.org/eng/minerals/sodium-and-chloride/deficiency Whitney, E., & Rolfes, S. (2016). Water and the Major Minerals. In Understanding Nutrition (14th ed.). Stamford, CT: Cengage Learning.

## 9.2.3 Requirements

Chloride is an essential or major mineral for humans and is considered an electrolyte. Suggested intake of chloride is between 750-900milligrams per day. Chloride recommendations are almost the same as sodium. The recommendations for chloride are higher than that of sodium. The average human body contains 115 grams of chloride. This means chloride makes up 0.15% of the total human body weight. Loss of chloride from the body happens when the body experiences diarrhea, heavy sweating, and/or vomiting. Too much blood chloride is only seen in cases of severe dehydration. Consuming ordinary foods that contain chloride can restore the chloride balance. Chloride deficiencies, although rare, can cause a life threatening condition called alkalosis. This condition refers to when the blood is overly alkaline. Symptoms of alkalosis include weakness, loss of appetite, irritability, and profound lethargy. An Excess intake of chloride results in water retention and high blood pressure. These side effects are due to the sodium and potassium that is always ingested along with chloride. Healthy individuals who consume enough water can tolerate large quantities of chloride.
Chloride in Diet. (2013, February 1). Retrieved December 3, 2015, from http://www.nytimes.com/health/guides/nutrition/chloride-in-diet/overview.html
Meletis N. D., C. (n.d.). Chloride: The Forgotten Essential Mineral. Retrieved December 3, 2015, from http://www.traceminerals.com/research/chloride
Whitney, E., & Rolfes, S. (2013). Understanding nutrition (14th ed.). Belmont, CA: Wadsworth.
The normal adult range for chloride is 97-107 mEq/L. It is recommended that healthy adults between the ages of 15 and 90 consume 2.3 grams of chloride per day in order to replace the amount of chloride lost each day due to sweating. Women who are pregnant or persons who are ill require a higher intake of chloride. The best way to get the suggested daily requirement of chloride is to plan for a diet that contains a variety of foods.
Dietary Reference Intakes: Water, Potassium, Sodium, Chloride, and Sulfate. (2004, February 11). Retrieved December 1, 2015, from http://iom.nationalacademies.org/reports/2004/dietary-reference-intakes-water-potassium-sodium-chloride-and-sulfate.aspx

## 9.2.4 Imbalance

Because chloride is an electrolyte, an imbalance can lead to very serious results, especially when coupled with a disease such as cancer. However, it is very rare that our diets lack chloride because chloride is abundant in food. Nevertheless, chloride deficiencies can still occur as the result of other causes such as sweating, chronic diarrhea, and vomiting. Vomiting can cause a loss of hydrochloric acid in the stomach, which can lead to an acid-base imbalance. Diuretics can also cause a low blood chloride level. Illnesses such as kidney and adrenal gland problems can also cause a low blood chloride level. Alkalosis is a life-threatening condition that results from a chloride deficiency. Symptoms of alkalosis include muscle weakness, loss of appetite, irritability, dehydration, and lethargy.
The only known cause of elevated blood chloride is dehydration. An elevated blood chloride level can result in an increased blood pressure along with a buildup of fluid in people with congestive heart failure, cirrhosis, or kidney disease. Chloride toxicities have only been observed in humans with an impaired sodium chloride metabolism (e.g. congestive heart failure)
Electrolyte Imbalance. (n.d.). Retrieved December 1, 2015, from http://cancer.unm.edu/cancer-info/cancer-treatment/side-effects-of-cancer-treatment/less-common-side-effects/blood-test-abnormalities/electrolyte-imbalance/ Sodium and Chloride. (2012, February 25). Retrieved December 1, 2015, from http://www.nutri-facts.org/eng/minerals/sodium-and-chloride/deficiency
Chloride imbalance can affect the body’s ability to metabolize food sources efficiently and correctly (Chemocare, Hyperchloermia, 2015). Remember that chloride is an electrolyte and when electrolytes are dissolved in water, they disassociate into positive and negative ions (Chemocare, Electrolyte Imbalance, 2015). These charged ions move in and out of cells and affect the body’s nerve and muscle function (Chemocare, Electrolyte Imbalance, 2015). Chloride ions are negatively charged and must be balanced with positively charged ions when entering and leaving cells, and too much or too little chloride can cause an electrolyte imbalance. Electrolyte imbalance can lead to irregular heartbeat, confusion, muscle spasms, numbness, fatigue, and nerve or bone disorders (Chemocare, Electrolyte Imbalance, 2015). Imbalance can be caused by both high levels and low levels of chloride in the blood. The kidneys control acid-base balance in the body, and thus they determine the level of chloride in the blood (Yeung, 2014). The normal level of chloride in the blood of an adult is 97-107 mEq/L (Chemocare, Hyperchloermia, 2015). Hypochloremia is a low level of chloride in the blood and it can be caused by body fluid loss— by continued vomiting diarrhea or sweating—or by the intake of drugs such as bicarbonates, corticosteroid, diuretics, and laxative (Chemocare, Hypochloremia, 2015). Hypochloremia can cause metabolic alkalosis, one of the most common electrolyte and fluid disorders (Palmer& Alpern, 1997). Metabolic alkalosis is a condition in which the blood contains an excessive amount of bases, throwing off its pH balance; it can be caused by a loss of acids or the presence of too much bicarbonate (Lewis, 2015). Symptoms include muscle cramps and spasms and irritability (Lewis, 2015). Hyperchloremia is a condition in which there are high levels of chloride in the blood, and it can be caused by high levels of sodium in the blood, as well as body fluid loss (Chemocare, Hyperchloermia, 2015). Additionally hyperchloremia can be a direct effect of kidney failure or diabetes (Chemocare, Hyperchloermia, 2015). Intake of drugs such as androgen, corticosteroids, estrogens, and some diuretics can also induce hyperchloremia (Chemocare, Hyperchloermia, 2015). Hyperchloremia can cause metabolic acidosis, which is the converse of metabolic alkalosis (Yeung, 2014). Metabolic acidosis is an excessive presence of acids in the blood and a loss of bicarbonate from the blood (Lewis, 2015). As the acid increases in the blood, the body’s buffering system may not be able to handle the stress (Lewis, 2015). The blood pH drops, and the kidneys excrete more acid in the urine in an attempt to compensate (Lewis, 2015). Another mechanism that the body stimulates in order to combat the rising acidity of the blood is the regulation of breathing: the brain tells the body to breathe deeper and faster in order to increase carbon dioxide exhalation (Lewis, 2015). If both of these systems become too overburdened and fail, it can eventually lead to a coma (Lewis, 2015). Symptoms include fatigue, vomiting, and nausea, as well as, an increased rate of breathing (Lewis, 2015).
Electrolyte Imbalance. (n.d.). Retrieved December 2, 2015, from http://chemocare.com/chemotherapy/side-effects/electrolyte-imbalance.aspx Hyperchloremia (High Chloride). (n.d.). Retrieved December 2, 2015, from http://chemocare.com/chemotherapy/side-effects/hyperchloremia-high-chloride.aspx Hypochloremia (Low Chloride). (n.d.). Retrieved December 2, 2015, from http://chemocare.com/chemotherapy/side-effects/hypochloremia-low-chloride.aspx Lewis, J. (2015). Overview of Acid-Base Balance - Hormonal and Metabolic Disorders. Retrieved December 2, 2015, from http://www.merckmanuals.com/home/hormonal-and-metabolic-disorders/acid-base-balance/overview-of-acid-base-balance Palmer, B. (1997). Metabolic alkalosis. Journal of the American Society of Nephrology, 8(9), 1462-1469. Retrieved December 2, 2015, from http://jasn.asnjournals.org/content/8/9/1462.short Yeung, S. (2014, July 9). Hyperchloremic Acidosis: Background, Etiology, Patient Education. Retrieved December 2, 2015, from http://emedicine.medscape.com/article/240809-overview#a6