| A11CC01 (WHO)|
| Drisdol, Calcidol, others|
US: A (No risk in human studies) and C
Ergocalciferol, also known as vitamin D2 and calciferol, is a type of vitamin D found in food and used as a dietary supplement. As a supplement it is used to prevent and treat vitamin D deficiency. This includes vitamin D deficiency due to poor absorption by the intestines or liver disease. It may also be used for low blood calcium due to hypoparathyroidism. It used by mouth or injection into a muscle.
Excessive doses can result in increased urine production, high blood pressure, kidney stones, kidney failure, weakness, and constipation. If high doses are taken for a long period of time tissue calcification may occur. It is recommended that people on high doses have their blood calcium levels regularly checked. Normal doses are safe in pregnancy. It works by increasing the amount of calcium absorbed by the intestines and kidneys. Food in which it is found include some mushrooms.
Ergocalciferol was first described in 1936. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. Ergocalciferol is available as a generic medication and over the counter. In the United Kingdom a typical dose costs the NHS less than 10 pounds a month. Certain foods such as breakfast cereal and margarine have ergocalciferol added to them in some countries.
Ergocalciferol may be used as a vitamin D supplement, and a 2011 clinical guideline considered ergocalciferol to be as effective as cholecalciferol (vitamin D3) which is produced naturally by the skin when exposed to ultraviolet light.
Both forms appear to have similar efficacy in ameliorating rickets and reducing the incidence of falls in elderly patients.
Ergocalciferol is a secosteroid formed by a photochemical bond breaking of a steroid, specifically, by the action of ultraviolet light on ergosterol.
Viosterol, the name given to early preparations of irradiated ergosterol, is essentially synonymous with ergocalciferol.
Ergocalciferol is manufactured and marketed under various names, including Deltalin (Eli Lilly and Company), Drisdol (Sanofi-Synthelabo) and Calcidol (Patrin Pharma).