Which two nutrients aid in maintaining fluid balance of the body?

Which two nutrients aid in maintaining fluid balance of the body?

• A. Protein and water
• B. Carbohydrates and fats
• C. Sodium and potassium
• D. Fiber and vitamins

Answer: (A)

Fluid balance is controlled by electrolytes that govern how water moves between the body's fluid compartments. Sodium, mostly outside cells, and potassium, mostly inside cells, create osmotic gradients that pull water where it’s needed and help regulate both extracellular fluid volume and intracellular hydration. Water is essential for hydration, but it doesn’t by itself determine where water sits in the body—the electrolytes do that. Protein can influence blood volume by maintaining oncotic pressure, which helps keep fluid inside vessels, but it isn’t the primary driver of the distribution of water between compartments. Other listed nutrients don’t directly regulate this osmotic balance. So, the two nutrients that best explain maintaining fluid balance are the electrolytes sodium and potassium.

Fluid balance is controlled by electrolytes that govern how water moves between the body's fluid compartments. Sodium, mostly outside cells, and potassium, mostly inside cells, create osmotic gradients that pull water where it’s needed and help regulate both extracellular fluid volume and intracellular hydration. Water is essential for hydration, but it doesn’t by itself determine where water sits in the body—the electrolytes do that.

Protein can influence blood volume by maintaining oncotic pressure, which helps keep fluid inside vessels, but it isn’t the primary driver of the distribution of water between compartments. Other listed nutrients don’t directly regulate this osmotic balance.

So, the two nutrients that best explain maintaining fluid balance are the electrolytes sodium and potassium.