Excessive doses can result in vomiting, constipation, weakness, and confusion. It may not be effective in people with severe kidney disease. Cholecalciferol is made in the skin following UVB light exposure. It is converted into calcifediol by the liver and into calcitriol by the kidney.
One of its actions is to increase the uptake of calcium by the intestines. It is found in food such as some fish, cheese, and eggs. Certain foods such as milk have cholecalciferol added to them in some countries. Cholecalciferol 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. In the United States treatment costs less than 25 USD per month.
Main article: Vitamin D deficiency
As a medication, cholecalciferol may be taken as a dietary supplement to prevent or to treat vitamin D deficiency.
Many question whether the current recommended intake is sufficient to meet physiological needs. Individuals without regular sun exposure, the obese, and darker skinned individuals all have lower blood levels and require more supplementation. A much less common use of cholecalciferol therapy in rickets utilizes a single large dose and has been called stoss therapy. Treatment is given either orally or by intramuscular injection of 300,000 IU to 500,000 IU , in a single dose, or sometimes in two to four divided doses.
A meta-analysis of 2007 concluded that daily intake of 1000 to 2000 IU per day of vitamin D3 could reduce the incidence of colorectal cancer with minimal risk. Supplements are not recommended for prevention of cancer as any effects of cholecalciferol are very small. Although significant correlations exist between low levels of blood serum cholecalciferol and higher rates of various cancers, multiple sclerosis, tuberculosis, heart disease, and diabetes, the consensus is that supplementing levels is not beneficial.
Cholecalciferol is one of the five forms of vitamin D. Cholecalciferol is a secosteroid, that is, a steroid molecule with one ring open.