Which of the following electrolytes plays a crucial role in the regulation of water balance in the body, particularly in the kidneys?

A Sodium ✓
B Potassium
C Calcium
D Magnesium

Explanation

Sodium plays a critical role in regulating water balance in the body, particularly in the kidneys, where it helps control the amount of water reabsorbed into the bloodstream.

Source

Berne and Levy Physiology
Electrolytes and Acid-Base Balance Physiology Electrolyte Regulation Easy MEDICAL Confidence: high