Sodium (Na)

What is sodium?

Sodium is a nutrient that our bodies need for fluid balance, muscle function, and other essential processes. Sodium is also called an electrolyte, because it generates an electrical charge in the body. Since we cannot produce sodium by ourselves, we must get it through our diet.

Why we need it

One of the major functions of sodium is regulating fluid balance. Sodium draws water out of our cells and into our bloodstream, which helps increase our blood volume (and thus, blood pressure). When our blood pressure becomes too low, our kidneys limit how much sodium is excreted through the urine, which helps our blood pressure return to a normal level.¹

We also need sodium to keep our muscles functioning properly. Sodium works with potassium (another essential nutrient) to maintain the cell membrane potential, which is the difference in electrical charge inside versus outside of our cells.² This movement of sodium and potassium across our cell membranes is essential for transmitting nerve signals and generating muscle contractions.²

Where it’s found

Sodium is abundant in foods, so you should have no trouble getting enough of it. Most of the sodium we eat is from processed or packaged foods. This includes things like deli meat, cheese, chips, and crackers. Additionally, sodium is found in many condiments, including soy sauce, salsa, barbecue sauce, and salad dressings. Sodium is also present in milk, bread, and many canned foods (e.g., beans, soups, and vegetables). Fresh fruits and vegetables tend to be quite low in sodium. Celery is one exception, as it’s naturally higher in sodium compared to most vegetables.

Daily requirements

The daily recommended amount of sodium is 120-370 milligrams (mg) for infants, 1000-1200 mg for children aged 1-8 years, 1500 mg for people aged 9-50 years, 1300 mg for people aged 51-70 years, and 1200 mg for people over the age of 70.³

Most people consume well beyond these recommended amounts. In the United States, more than 80% of women and more than 90% of men consume excessive amounts of sodium.⁴

Sodium deficiency

Since sodium is so prevalent in food, deficiency is very rare. Nonetheless, it is possible. Sodium deficiency (also called hyponatremia) is usually caused by medical conditions like kidney disease or heart failure.⁵ It can also be caused by excessive sweating, diuretic use, or drinking too much water (which can dilute sodium in the body).⁵ Symptoms of sodium deficiency include dizziness, nausea, vomiting, and muscle cramping. It can also lead to seizures or coma in severe cases.⁵

Can you get too much sodium?

Sodium can be harmful when consumed in high amounts. Excess sodium consumption can increase your risk of developing hypertension (high blood pressure). Hypertension is linked with many negative outcomes, including heart disease, stroke, pregnancy complications, and kidney disease.⁶

We are recommended to consume no more than 2300 mg of sodium per day. This number is the Chronic Disease Risk Reduction Intake (or CDRR), which is the maximum amount of a nutrient that is recommended to minimize chronic disease risk.³

Fun facts

The terms sodium and salt are often used interchangeably, although they are technically not the same thing. Salt is made up of 40% sodium and 60% chloride (another essential nutrient). For reference, one teaspoon of salt provides about 2300 mg of sodium.

Sodium is added to processed food for many reasons, beyond just flavor. For instance, sodium can contribute to the texture, color, and shelf life of foods.⁶ Sodium also supports fermentation, as it helps ward off harmful bacteria. This is why many fermented foods (e.g., salami, pickles, and cheese) have a strong salty taste.⁷