Cholecalciferol
Prescription status is set country by country — the label where you live is the one that applies.
Beta: the medication section is still being tested, and its data may contain errors. Do not rely on it for a decision about your own treatment.
Cholecalciferol is vitamin D3, the same form of the vitamin the skin makes on exposure to sunlight. The body converts it in the liver and kidney into the active hormone that governs how much calcium is absorbed from food and how bone mineral is laid down and released. It is used to correct or prevent vitamin D deficiency, to support bone health, and, in the way it is commonly taken, for general immune support.
A usual adult range, not a national label — the dose and the timing differ by country and by product.
Approved uses differ by country — some of these may be off-label or unapproved where you live.
Vitamin D is fat-soluble, so it is absorbed better when taken with a meal that contains some fat; the morning timing is a matter of routine rather than pharmacology. Combination products and separate supplements that pair it with calcium carbonate add to the same calcium load, so it is worth knowing what else is being taken. Because the whole point of the vitamin is to raise calcium absorption, a large or long-running intake can push blood calcium above the normal range, which is why 25-OH vitamin D along with total and ionised calcium are the values usually checked.
Signs that blood calcium may have risen too far — unusual thirst, frequent urination, nausea, constipation, muscle weakness or confusion — are a reason to see a doctor rather than adjust things by guesswork. The same applies if a blood test shows calcium above the reference range.
Reference information, not medical advice. Discuss any change with your doctor.