Giving Life: The Periodic Table

The human body is pretty amazing — it’s an incredible collaboration of chemical elements.

Maybe you tried to memorize the elements on the periodic table in high school chemistry. Maybe you even learned about some of them… but do you really know how these elements keep our muscles, organs, and nerves in good working order?

“Do you really know how these elements keep our muscles, organs,
and nerves in good working order?”

You probably know the human body is primarily made up of oxygen, carbon, hydrogen and nitrogen — so you might assume these elements do all of the hard work.1 But roughly four percent of the human body is made up of other key elements that are critical for life. If they get out of balance, it can present serious health risks and can even be lethal.

The Key Elements

Key elements — sodium, chloride, potassium, calcium and magnesium — are actually all electrolytes2 that help control a wide range of functions, such as:3

  • energy production
  • muscle contractions
  • renal function
  • metabolism
  • the balance of fluid inside and outside of cells
  • cell signaling (the transmission of molecular signals from outside a cell to inside a cell)

Sodium (Na+) and chloride (Cl-)
When sodium and chloride are combined, they’re known as salt. Everyone knows salt can be found in processed meats and canned soups, but – perhaps more surprisingly – salt is also in unprocessed fruits and vegetables like brussels sprouts, cantaloupe, grapes and chickpeas.4

Sodium and chloride play a key role in maintaining proper fluid levels in the body, regulating blood flow and blood pressure, and facilitating communication between nerves and muscles in the body. Too much can lead to lethargy, muscle cramps, seizures and even death5, while not enough can cause confusion, headache and vomiting.6

Potassium (K+)
Bananas are the best-known food source for potassium, but plenty of other fruits and vegetables are also naturally high in potassium, like apricots, lentils, sweet potatoes and broccoli.7

Proper levels of potassium are important for cardiac activity, muscle function and neuron transmission. Too much potassium in the body, called hyperkalemia, may cause nausea, muscle fatigue, and can lead to dangerous changes in heart rhythms.8 In severe cases, hyperkalemia may be fatal. A deficiency of potassium, called hypokalemia, may lead to muscle cramping and fatigue.9

Calcium (Ca+)
When you think of calcium, you probably think of dairy products. But while milk, cheese and yogurt are good sources of calcium, so are leafy greens, seafood, legumes and fruit.10

It’s pretty common knowledge that calcium is needed to develop strong, healthy bones and teeth, but it’s also critical for muscle function, blood clotting and communication between nerves and muscles.11

Magnesium (Mg++)
Magnesium may not be as commonly discussed compared to some of the elements mentioned above, but can be found in a variety of foods including leafy greens, nuts, beans, brown rice, and even in coffee and teas.

Magnesium is needed for hundreds of biochemical reactions in the body and helps maintain normal nerve function and regular cardiac activity, as well as stabilize blood sugar. Although an excess of magnesium in healthy people is rare, it can contribute to an irregular heartbeat. Magnesium deficiency can lead to fatigue, muscle spasms and numbness.12

The Kidney’s Role13

Just like the complex network of nerves, muscles tissue and cells in the body, these key chemical elements don’t work exclusive of each other, and they don’t work in a vacuum, either. They rely on each other and on organs like the kidney to help maintain balance.

Despite what some may think, the kidney doesn’t just remove waste products and excess fluid from the body. It also helps regulate the levels of elements like potassium, sodium, and calcium in the bloodstream.

Case in point, almost all regulation of potassium excretion takes place in the kidney. More specifically, one of the million or so filtering units within the kidney decides how much potassium is excreted from the body, all based on two principle factors.

The first factor influencing the kidney’s filtering of potassium is how much and how quickly fluid is moving through the kidney as well as the amount of sodium and chloride in the kidney at the time. The higher the rate of flow and amount of sodium and chloride, the more potassium is secreted. The lower the rate of flow and amount of sodium and chloride, the less potassium is secreted.

The second factor influencing the kidney’s filtering is the effect of aldosterone, a steroid hormone that helps regulate salt and water in the body. The higher the aldosterone levels in the setting of the aldosterone-sensitive tissues of the kidney, the more potassium is secreted.

As this example shows, balance is everything.

Survive and Thrive

It’s important for the body to maintain balance between potassium, sodium, calcium and other elements, because, as stated earlier, an imbalance of these can lead to dangerous changes in the body’s many functions, like cardiac activity. Hyperkalemia, which you’ll recall is a higher than normal level of potassium in the blood, is a common cause of abnormal heart rhythm.13

When we learned about the periodic table way back when, it may have just seemed like abstract science. However, the elements represented in the periodic table are essential to our survival on a second-by-second basis.

Learning more about what these chemical elements do and how they work together enables us to better understand how the body functions and what we can do to survive and thrive.


1. Black, J. Biological Performance of Materials Fundamentals of Biocompatibility. Fourth ed. Florida: CRC Press; 2006. Chapter 14, Mineral Metabolism; p. 273.

2. Fluid and Electrolyte Balance. Summary. MedlinePlus. Accessed September 28, 2016.

3. Minerals: What They Do, Where to Get Them. Texas Heart Institute. Accessed September 28, 2016.

4. Best of: Sodium. Fruits & Veggies More Matters. Accessed September 28, 2016.

5. Signs and Symptoms; Hypernatremia. Accessed September 28, 2016.

6. Signs and Symptoms; Hyponatremia. Accessed September 28, 2016.

7. Best of: Potassium. Fruits & Veggies More Matters. Accessed September 28, 2016.

8. Symptoms. High Potassium (Hyperkalemia). Mayo Clinic. Accessed September 28, 2016.

9. Syptoms. Low Potassium (Hypokalemia). Mayo Clinic. Accessed September 28, 2016.

10. Calcium Content of Common Foods. International Osteoporosis Foundation. Accessed September 28, 2016.

11. Calcium in Diet. MedlinePlus. Accessed September 28, 2016.

12. Magnesium. National Institutes of Health. Accessed September 28, 2016.

13. Weisberg, Lawrence S. Management of Severe Hyperkalemia. Crit Care Med. 2008; Vol. 36, No. 12; p. 3247-3251.