Yes, calcitonin affects calcium levels in the body. Its primary function is to regulate and lower blood calcium levels when they become elevated. Calcitonin inhibits bone resorption by osteoclasts, reducing the breakdown of bone tissue and the release of calcium into the bloodstream. Simultaneously, it promotes the excretion of calcium through the kidneys, enhancing calcium elimination in the urine. These actions work together to lower blood calcium levels and maintain calcium homeostasis. In this sense, calcitonin plays a vital role in the regulation of calcium metabolism in the body.