Electrolytes: Hydration & Optimal Cellular Function

Ionic conductivity, combined with the human body’s increased water content, is why our body is a good “conductor” of electricity. This function is vital for our viability and survival, as these charged particles (electrolytes or ions, particles that, when dissolved in bodily fluids, carry a positive or negative electrical charge) are largely responsible for carrying out vital functions, such as maintaining tissue hydration, maintaining normal pH, and facilitating communication between the brain and the rest of the body, via the nervous system.

Electrolytes, then, are the “carriers” of this ionic conductivity and are extremely important for the survival and optimal functioning of the human body. They are the minerals our body needs in large quantities, which is why you may have heard them referred to as macrominerals.

Let’s get to know them!

Sodium. The most important extracellular electrolyte.

Potassium. The most important intracellular electrolyte.

Chlorine. Together with sodium, it is responsible for maintaining hydration in the extracellular environment.

Sodium, potassium, and chloride are the most important minerals, and their balance inside and outside cells plays a crucial role in maintaining hydration and, consequently, in cellular viability.

Calcium. Calcium ions are responsible for healthy muscle contraction, which our body performs so that we can carry out our daily activities.

Magnesium. Along with calcium (muscle contraction), magnesium acts in the “opposite” way, promoting muscle relaxation, playing a very important role in musculoskeletal health, and helping to prevent muscle cramps.

Bicarbonates & Phosphates. They play a very important role in maintaining normal pH levels in the body.

The key functions of electrolytes in the human body.

Optimal hydration. Maintaining our body’s hydration is inextricably linked to maintaining electrolyte balance. Our hydration depends on how well the body can retain water within the cells, and electrolytes—especially sodium, potassium, and chloride—play a crucial role in this process.

Maintaining normal pH. Along with maintaining fluid balance inside and outside cells, another vital mechanism based on electrolytes is acid-base balance and the maintenance of pH between 7.36 and 7.42—a very “delicate” balance.

Muscle Contraction. The human body’s ability to move and perform daily activities is directly linked to the “in-and-out” flow of electrolytes to and from muscle cells. The primary electrolyte for muscle movement is calcium, while magnesium plays a complementary role.

Nervous Communication. The daily generation and transmission of thousands of nerve impulses—signals—relies primarily on ionic conductivity, that is, the movement of electrolytes in and out of cells. In other words, if there is a lack of electrolytes, the connection between the brain and the rest of the body becomes impossible.

Which foods are good sources of electrolytes?

The most important dietary sources of electrolytes are fruits, vegetables, salted nuts, and dairy products. The easiest electrolytes to replenish are sodium and chloride, as these are minerals found in high concentrations in many foods we consume daily, and salt (sodium chloride) is added to many processed foods in our daily diet (e.g., cheese and toast bread, packaged products, etc.). However, requirements for potassium, calcium, and magnesium require attention and are adequately met by food groups in daily dietary habits.

More specifically, we have the following rich dietary sources per electrolyte (see table)

What happens when we become dehydrated? In what situations do we need to increase our intake of electrolytes?

Dehydration—that is, the loss of fluids and electrolytes—even to a small degree, can cause significant symptoms, such as:

• Dizziness
• Confusion
• Weakness, intense feeling of fatigue
• Muscle cramps, delayed muscle recovery
• Headache
• Nausea

We’ve all experienced severe dehydration, especially during the hot months of the year, and even more so if we sweat a lot. Through sweat, a significant percentage of electrolytes is lost, which need to be replenished immediately, especially in high temperatures. Athletes are much more prone to significant fluid and electrolyte loss due to their intense training regimen.

Even a fluid loss of just 1–2% of our body weight can cause the above symptoms and significantly impact athletic performance.

Finally, in cases of illness where the primary symptoms are diarrhea and vomiting, fluid losses increase rapidly and require immediate replenishment. The severe weakness and dizziness we experience after acute gastroenteritis stem from the significant electrolyte imbalance the body undergoes due to increased fluid loss.

In the above circumstances, that is, during the summer months, in extreme temperatures, with excessive sweating, during severe episodes of diarrhea and vomiting, as well as during demanding training periods—electrolyte supplements can be extremely helpful, as the replenishment they provide is immediate and effective.

Important note: Increased sodium intake requires caution, as it has been linked to high blood pressure and, in the long term, increases cardiovascular risk. If none of the above conditions apply, the extra salt in our diet becomes unnecessary and potentially harmful to our health.

In conclusion

Electrolytes are the most important group of minerals, which work together to ensure the proper functioning of the body’s essential processes, such as maintaining normal pH levels, optimal hydration, and the healthy functioning of neurons and muscles. Key sources include salt, fruits, nuts, and dairy products, which are essential components of our daily diet. In cases of significant fluid loss, such as during heavy sweating or in cases of diarrhea/vomiting, supplementation can be an extremely useful tool for immediate replenishment and for preventing the onset of more serious symptoms.

Scientific References

Franjic, S. (2025). Electrolytes are Important for the Proper Functioning of the Body.

Mahendra, A. (2023). An overview on electrolytes: Its importance, function, and imbalances. Clin Nutr Hosp Diet, 43(1), 01-02.

Mohammadifard, N., Gotay, C., Humphries, K. H., Ignaszewski, A., Esmaillzadeh, A., & Sarrafzadegan, N. (2019). Electrolyte minerals intake and cardiovascular health. Critical reviews in food science and nutrition, 59(15), 2375-2385.