volume definition, meaning, what is volume: the amount of space that is contained within an object or solid shape: . Learn more.
However, parathyroid hormone and calcitonin work together to control calcium levels in the blood. The blood calcium level is the main stimulus for the release of these hormones, as the release of these hormones is not controlled by the pituitary.
The skin, liver and kidneys work together to synthesize 1,25-diydroxyvitamin D (calcitriol), the active form of vitamin D, which helps maintain normal levels of calcium and phosphorus in the blood. In the skin, a molecule made from cholesterol is converted to vitamin D by exposure to ultraviolet rays from the sun.