Name atleast two hormones which result in fluctuation of `Ca^(2+)` level.

Explanation

Parathyroid hormone and calcitonin results in the fluctuation of `Ca^(2+)` level. Parathyroid Hormone (PTH) increases the `Ca^(2+)` levels in the blood. PTH acts on the bones and stimulates the process of bone resorption (dissolution/demineralisation).
PTH also stimulates reabsorption of `Ca^(2+)` by the renal tubules and increases `Ca^(2+)` absorption from the digested food.
Calcitonin is a 32-amino acid linear polypeptide hormone, that is produced in humans levels opposing tha effect of Parathyroid Hormone (PTH).