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Unlike the other twelve vitamins, vitamin D is only conditionally essential - in a preindustrial society people had adequate exposure to sunlight and the vitamin was a hormone, as the primary natural source of vitamin D was the synthesis of cholecalciferol in the lower layers of the skin’s epidermis, triggered by a photochemical reaction with ...
Calcitriol is a hormone and the active form of vitamin D, normally made in the kidney. [8] [9] [10] It is also known as 1,25-dihydroxycholecalciferol.It binds to and activates the vitamin D receptor in the nucleus of the cell, which then increases the expression of many genes. [11]
[1] [2] Lanolin, a waxy substance that is naturally secreted by wool-bearing mammals, contains 7-DHC which is converted into vitamin D by sunlight and then ingested during grooming as a nutrient. In insects 7-dehydrocholesterol is a precursor for the hormone ecdysone, required for reaching adulthood.
Cholecalciferol is a form of vitamin D which is naturally synthesized in skin and functions as a pro-hormone, being converted to calcitriol. This is important for maintaining calcium levels and promoting bone health and development. [4] As a medication, cholecalciferol may be taken as a dietary supplement to prevent or to treat vitamin D ...
The VDR gene encodes the nuclear hormone receptor for vitamin D. The most potent natural agonist is calcitriol (1,25-dihydroxycholecalciferol) and the vitamin D 2 homologue ercalcitriol, 1-alpha,25-dihydroergocalciferol) is also a strong activator. Other forms of vitamin D bind with lower affinity, as does the secondary bile acid lithocholic ...
The following is a list of hormones found in Humans. Spelling is not uniform for many hormones. Spelling is not uniform for many hormones. For example, current North American and international usage uses [ citation needed ] estrogen and gonadotropin, while British usage retains the Greek digraph in oestrogen and favours the earlier spelling ...
Most people in the world depend on the sun to get vitamin D, [31] and elderly populations in low UVB countries experience higher rates of cancer. [32] There are not many foods that naturally have vitamin D. [33] Examples are cod liver oil and oily fish. If people cannot get sunlight, then they will need 1,000 IU of vitamin D per day to stay ...
These two forms of vitamin D are metabolized in the liver and stored as 25-hydroxyvitamin D. [4] Before biological use, the storage form must be converted into an active form. One common active form is 1,25-dihydroxyvitamin D. [4] The term vitamin D in this article means cholecalciferol, ergocalciferol, 25-hydroxyvitamin D, and the active forms ...