What ions does aldosterone primarily cause to be retained or lost in the urine?

Aldosterone plays a crucial role in the regulation of electrolyte balance in the body, particularly in the kidneys. It is a steroid hormone produced by the adrenal cortex and primarily acts on the distal convoluted tubule and collecting ducts of the nephron.

The principal actions of aldosterone include promoting the reabsorption of sodium ions from the urine back into the bloodstream, which helps to maintain blood volume and pressure. In conjunction with sodium retention, aldosterone also increases the excretion of potassium and hydrogen ions into the urine. This process is vital for maintaining electrolyte balance, preventing hyperkalemia (high potassium levels), and ensuring the body's acid-base balance.

The retention of sodium leads to water retention, contributing to increased blood volume and pressure. The simultaneous excretion of potassium and hydrogen ions can also influence acid-base homeostasis in the body, as excess hydrogen ions are associated with acidosis.

Thus, the correct answer emphasizes aldosterone's primary function of retaining sodium while promoting the loss of potassium and hydrogen, which is consistent with its role in regulating electrolyte balance within the body.