Which hormone lowers blood calcium level?

The hormone that lowers blood calcium level is Calcitonin. Here are the steps of how it works:

1. Calcitonin is produced by the parafollicular cells (also known as C cells) in the thyroid gland.
2. When the levels of calcium in the blood are high, these C cells are stimulated to release Calcitonin.
3. Calcitonin then acts on the bones, kidneys, and the intestines to reduce the level of calcium in the blood.
   • In bones, it inhibits the activity of osteoclasts, the cells that break down bone to release calcium into the blood.
   • In kidneys, it increases the amount of calcium excreted in the urine.
   • In intestines, it reduces the absorption of calcium.
4. As a result, the level of calcium in the blood decreases.