Close to a hormone and a vitamin at the same time, cholecalciferol or vitamin D3 is completely produced at the skin level under the direct influence of sunlight. The structure of vitamin D3 is close to that of certain steroids such as cortisol, testosterone and cholesterol, and the substance is present under various forms within the body system. There is an inactive and an active type of vitamin D3, and then, there is the one known as the blood-calcium form. When health tests are performed, the level of all these vitamin D3 varieties is measured. One form results from the other: the first is produced by the skin, carried to the liver and then sent to the kidneys where it gets is pro-hormone form.



Food fortification relies on vitamin D3, as this is the most important one in the group, with a major role in the processing of both calcium and phosphorus. If we were to compare vitamin D3 and vitamin D2, the former is definitely considered more potent and with longer lasting effects, but it also requires careful administration in supplements. There is a limit of body tolerance for vitamin D3 intakes which should not be overpassed; hence, make sure to never administrate it without consulting your doctor first.

To fully understand the function of the vitamin D3 we should stress the fact that it helps the processing of the calcium at the intestine level favoring its absorption in the system. Nevertheless, when too much vitamin D3 is administered, there is a whole range of problems that can appear, and they are all connected to too high an amount of calcium in the blood. A decrease in the renal function and the so-called hypercalcemia are the symptoms to be expected after too large vitamin D3 intakes. A precaution measure to avoid further health problems is to adjust the vitamin dosage in the case of patients with a renal dysfunction.

The proper dosage of vitamin D3 should be kept below 2000 IU/day in case you take any supplement; otherwise this must-have chemical can be taken from food. Besides margarine, milk and cereals fortified with vitamin D3, this oil-soluble substance is to be found in cod liver, salmon, mackerel and tuna. Therefore, people who focus their diets of fish products are less likely to suffer from vitamin D3 deficiency or hypocalcemia. Thus, food and sun exposure should ensure the proper amount of cholecalciferol necessary for the proper functioning of the body.