Now, the second type of hormone released by our kidneys is calcitriol. And calcitriol is actually a lipid soluble hormone that is an active form of vitamin D. And what it basically does is it stimulates the increase in the calcium and phosphate ion concentration inside our blood. So this is basically used to control and regulate the amount of calcium found inside our blood. So it is stimulated, it is released when we have a low concentration of calcium in the blood. And what it does is it ultimately increases the amount of calcium inside our blood by two methods. Firstly, it increases the ability of our cells in the gut and our intestines to basically absorb more calcium from our food and more phosphate ons from our food.