What is cholecalciferol?
Cholecalciferol (colecalciferol) is one of the most important compounds in the vitamin D group. It is also known as vitamin D3 or calciol.
The body can cover a small part of its need for cholecalciferol through food, more precisely through animal foods such as fatty fish and fish liver oil (cod liver oil). However, it can produce the majority of the required amount itself from cholesterol, namely in the skin with sufficient sun exposure.
Strictly speaking, cholecalciferol is therefore not a vitamin (= a substance that is important for life and must be taken in with food because the body cannot produce it itself). Rather, it is a hormone precursor (prohormone):
Both the cholecalciferol supplied with food and that produced in the skin itself is first converted in the liver into calcifediol (calcidiol) – the storage form of cholecalciferol. From this, the hormone calcitriol (1,25-dihydroxy-cholecalciferol) – the biologically active form of vitamin D – can be formed in the kidneys and other tissues as required.
Cholecalciferol preparations
For the prevention and treatment of vitamin D deficiency diseases (such as rickets and osteoporosis), doctors use vitamin D preparations which, depending on the dosage, are classified as drugs or dietary supplements. These are very often preparations containing cholecalciferol. Sometimes combination preparations with cholecalciferol and calcium are also used.
For the industrial production of cholecalciferol, animal source materials are generally used, for example lanolin – the wool wax of sheep (cholecalciferol is obtained from the cholesterol extracted from this by UV irradiation).
Such cholecaciferol preparations from animal sources are often a problem for vegans. However, there are now also preparations in which the vitamin D3 is obtained from lichen.
What side effects can occur?
The “natural” supply via self-produced cholecalciferol or cholecalciferol ingested with food poses no risk to the body. The situation is different if the hormone precursor is taken as a medication or dietary supplement:
The excess calcium can trigger nausea, vomiting, psychological symptoms, loss of consciousness and cardiac arrhythmia, for example. The kidneys are also affected – especially if there is a prolonged excess of calcium:
The organs can then no longer concentrate urine sufficiently, which results in increased urination (polyuria) and a very strong feeling of thirst (polydipsia). This can lead to the formation of kidney stones and kidney damage, including kidney failure (life-threatening!).
Only take vitamin D supplements on the advice of a doctor and adhere to the recommended dosage and duration of use!
What effect does cholecalciferol have?
Cholecalciferol itself has no effect in the body, but is inactive. However, as mentioned above, it serves as a starting material for the hormone calcitriol – the active form of vitamin D. The body needs this primarily for the regulation of the calcium and phosphate balance and thus for the mineralization of the bones. You can find more detailed information about the effect of calcitriol here.
