Which hormone regulates sodium levels in the body?

Which hormone regulates sodium levels in the body?

• A. Cortisol
• B. Insulin
• C. Aldosterone
• D. Thyroxine

Answer: (C)

Aldosterone is the primary hormone responsible for regulating sodium levels in the body. It is produced by the adrenal cortex and plays a crucial role in the renin-angiotensin-aldosterone system (RAAS), which helps control blood pressure and fluid balance. When sodium levels in the blood are low or when there is a decrease in blood volume or blood pressure, the secretion of aldosterone increases. This leads to the reabsorption of sodium from the kidneys back into the bloodstream, which in turn helps to retain water and increase blood volume, thereby improving blood pressure and overall fluid balance.

Cortisol does have some influence over sodium metabolism but primarily affects carbohydrate metabolism and is more related to stress responses. Insulin regulates glucose and fat metabolism and has a minor role in potassium levels but does not directly regulate sodium levels. Thyroxine, produced by the thyroid gland, primarily regulates metabolism and energy levels rather than sodium homeostasis. Hence, the distinctive role of aldosterone in sodium regulation clearly identifies it as the correct answer.