Which hormone raises blood calcium levels in the human body?
Answer
Parathyroid hormone
Parathyroid hormone raises blood calcium levels in the human body.
Usually abbreviated PTH, this hormone is produced by the parathyroid glands, typically four small glands located behind the thyroid gland in the neck. Specialized cells release more PTH when calcium concentration in the blood falls.
PTH acts on bones, kidneys, and indirectly on the intestines. It promotes the release of calcium from bone tissue, reduces calcium loss through urine, and stimulates the kidneys to activate vitamin D. Active vitamin D then increases calcium absorption from food in the intestine.
Calcitonin is a frequent source of confusion because it generally lowers blood calcium and is produced by thyroid C cells. PTH is not the same as parathyroid hormone-related protein, which has related effects but is a different molecule. Calcium regulation also involves phosphate balance, especially through the kidneys.