<unk> , also known as vitamin<unk>  and<unk> , is a type of vitamin D that is made by the skin when exposed to sunlight; it is found in some foods and can be taken as a dietary supplement.<unk>  is made in the skin following UVB light exposure. It is converted in the liver to calcifediol (25-hydroxyvitamin D) which is then converted in the kidney to calcitriol (1,25-dihydroxyvitamin D). One of its actions is to increase calcium uptake by the intestines. It is found in food such as some fish, beef liver, eggs, and cheese. Milk, fruit juice, yogurt, and margarine also may have<unk>  added to them in some countries, including the United States.<unk>  can be taken as an oral dietary supplement to prevent vitamin D deficiency or as a medication to treat associated diseases, including rickets. It is also used for familial hypophosphatemia, hypoparathyroidism that is causing low blood calcium, and Fanconi syndrome. Vitamin-D supplements may not be effective in people with severe kidney disease. Excessive doses in humans can result in vomiting, constipation, weakness, and confusion. Other risks include kidney stones. Doses greater than 40,000IU (1,000μg) per day are generally required before high blood calcium occurs. Normal doses, 800–2000 IU per day, are safe in pregnancy.<unk>  was first described in 1936. It is on the World Health Organization's List of Essential Medicines. In 2019, it was the 84th most commonly prescribed medication in the United States, with more than 9million prescriptions.<unk>  is available as a generic medication and over the counter.<unk>  is used (at much higher) doses to kill rodents.
Cholecalciferol
Ergocalciferol
Calcitriol
Calcium/cholecalciferol
Folate
Tocopherol
Calamine
Retinol