The role of salt in nutrition

Published 3:19 pm Tuesday, February 28, 2023

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Last week, we wrapped up our study of sugar, so I thought it would be fitting to follow with a study of salt. Did you know that even though too much sugar or salt in the body can produce detrimental effects, both are necessary for life? 

Now when we speak of salt, we’re specifically referring to its chemical composition, which is sodium chloride, written NaCl. Salt is composed of 39% sodium by weight, and 61% chloride. Salt’s two main sources are seawater and the sodium chloride mineral halite, also known as rock salt.

So, if we can’t live without salt, just why do we need it? First, the body requires chloride found within salt. In fact, chloride is, after sodium, the most abundant element found in the body. We need chloride for fluid balance, and to maintain proper blood volume, blood pressure, and pH of the body’s fluids. However, most of the nutritional attention these days is given to sodium. Sodium is so essential to life that humans have specific sensors on their tongues to detect it, and it can be found in absolutely every cell of the body. It plays a pivotal role in controlling the movement of fluids in and out of cells. 

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Most of the body’s sodium is located in the blood, and in the fluid between cells referred to as extracellular fluid. The mineral potassium is present in the fluid within cells, known as intracellular fluid. These concentration differences are due to the action of a membrane-active transport system that pumps sodium out of cells and potassium into them. This active transport system is known as the “sodium/potassium pump.” 

Though sodium and potassium are closely intertwined, they have opposite effects on the body. These two minerals must be in constant balance so nutrients and waste products can move across cell membranes. Blood sodium concentrations that are too high are called hypernatremia, while high blood potassium levels are known as hyperkalemia. 

Sodium also plays a role in blood volume. To maintain blood volume within a normal range, the kidneys regulate the amount of water and sodium lost in the urine. Sodium also has a direct effect on the transmission of electrical impulses (sodium is an electrolyte, as is potassium), muscle contraction, and vasoconstriction, particularly in larger arteries, and small arterioles. 

In a nutshell, the body requires a small amount of sodium every day to conduct nerve impulses, contract and relax muscles, and maintain the proper balance of water and minerals. According to the American Heart Association, the minimum physiological requirement for sodium is less than 500 mg a day, or about one teaspoon of salt.

Here are a few facts about salt that you might not know. 

Salt was once so valuable that Roman soldiers were sometimes paid with it. In fact, the word “salary” comes from the Latin word “sal,” for salt. 

After all the information and news about salt in foods, you might be surprised to know that the number one use for salt in the United States has nothing to do with food at all. Roughly 44 percent of the salt in our country goes toward de-icing roads, according to the U. S. Geological Survey. 

While eating, sea turtles ingest a large amount of salt from seawater. To get rid of this excess salt, they have specialized glands near their eyes that release excess salt in higher concentrations than the surrounding seawater. That’s why to many folks who observe sea turtles on land, they appear to be crying. 

We’ll conclude our study of salt next week.  

There’s one more week to sign up for my free nutritional and fitness consultations. Just go to my email address to sign up, and I’ll be in touch. 

David Crocker is a nutritionist and master personal trainer. Questions? Email David at or text to 864-494-6215.