What hormones are produced by the kidneys?

• A. Growth hormone and thyroid hormone
• B. Erythropoietin and calcitrol
• C. Insulin and glucagon
• D. Aldosterone and cortisol

Answer: (B)

Kidneys help regulate blood and mineral balance by producing specific hormones. Erythropoietin signals the bone marrow to produce more red blood cells when oxygen delivery is low, supporting oxygen transport in the blood. Calcitriol, the active form of vitamin D, is formed in the kidneys and increases calcium and phosphate absorption from the gut, aiding bone health and mineral balance. The other hormones come from different organs: growth hormone from the pituitary, thyroid hormone from the thyroid, insulin and glucagon from the pancreas, and aldosterone and cortisol from the adrenal glands. So the kidneys produce erythropoietin and calcitriol.