Author/Editor		Homšak, Evgenija
Title		Vitamin D
Translated title		Vitamin D
Type		članek
Source		In: Monografija IV. osteoloških dnevov z mednarodno udeležbo Maribor : Univerzitetni klinični center
Publication year		2013
Volume		str. 161-174
Language		slv
Abstract		Vitamin D je v maščobah topni steroidni prohormon. V organizem ga dobimo na dva načina; v manjši meri s hrano ter v glavnem s sintezo v epidermisu kože pod vplivom delovanja UVB žarkov sonca. Poznani sta dve glavni obliki ergokalciferol (D2) in holekalciferol (D3), pri čemer se v telesu sintetizira le slednji. Njegov metabolizem v živalskih organizmih omogoča, da se v jetrih hidroksilira do 25-OH vitamina D, ki predstavlja glavno zalogo v organizmu, in nato šele v ledvicah z dodatno hidroksilacijo do 1,25-(OH)2 vitamina D doseže aktivno obliko, ki ima učinek na različne tarčne celice. Njegov pomen se je od njegovega odkritja (začetek 20. stoletja) pa dodanes razširil iz več vidikov. Tako je že vrsto let poznan njegov učinek na homeostazo in regulacijo nivoja kalcija in fosforja ter vpliv na razvoj obolenj kosti in mišic. Zadnja spoznanja pa so pokazala, da je njegov prohormonski učinek mogoč šele z vezavo na njegove receptorje VDR, ki se nahajajo tako v različnih normalnih humanih celicah, kot tudi v rakastih celicah. Zato je v zadnjem času velik povdarek tudi na njegovi hormonski vlogi kot regulatorja genov v različnih celicah. Na ta način lahko pomembno vpliva na razvoj različnih drugih obolenj (rak, kardiovaskularne, imunološke, nevrološke bolezni, diabetes).Vitamin D is a fat-soluble steroid hormone. The organism is obtained in two ways, to a lesser extent, with food, mainly in form of ergocalciferol (D2), and generally by the synthesis in the epidermis of skin under the influence of a UVB sun as cholecalciferol (D3). The metabolism of the animal organisms allows hydroxylation in the liver to 25-OH vitamin D, which is the main storage form of the organism. Further in the kidney by hydroxylation to 1,25-(OH)2 vitamin D reaches the active form, which has an effect on a varietyof target cells. Its importance since its discovery (early 20th century) to thepresent expanded in several respects. The role of vitamin D in homeostasis and regulation of the level of calcium and phosphate as well as maintaining bone health has been known for decades. Recently findings have shown that its prohormon effect, which is possible only by binding to its receptors VDR, islocated both in a variety of normal human cells, as well as in cancerous cells. Therefore, however, is a great emphasis on its hormonal role as a regulator of genes in different cells. In this way, the several studies try to confirm its significant effect on the prevention or development of a variety of other diseases (cancer, cardiovascular, immunologic, neurological diseases, diabetes).
Keywords		vitamin D prohormonski učinki VDR receptor metode določanja priporočene vrednosti vitamin D prohormon effects VDR receptor measurement methods recommended values