Which statement about sodium is true?

• A. Sodium does not affect water balance.
• B. Sodium has no role in electrolytes.
• C. Sodium is lost through sweating and is necessary to maintain hydration.
• D. Sodium should be avoided entirely to stay hydrated.

Answer: (C)

Sodium acts as a key regulator of fluid balance in the body, helping to maintain the right distribution of water between compartments and keep extracellular fluid volume stable. When you sweat, you lose not just water but also sodium, so replacing some of that sodium is important for staying hydrated, especially during prolonged or intense activity in heat. That’s why the statement about sodium being lost through sweating and being necessary to maintain hydration is true. Sodium plays a major role in electrolyte balance and supports nerve and muscle function, so it isn’t something to avoid entirely; during longer workouts or hot conditions, including a bit of sodium in your hydration can help maintain fluid balance and performance.