diplomsko delo
Ema Luna Karara Geršak (Author), Marko Kreft (Reviewer), Evgen Benedik (Mentor)

Abstract

Vitamin D je prohormon, ki se lahko endogeno sintetizira v koži ali zaužije s hrano in prehranskimi dopolnili oziroma zdravili. Dve glavni obliki vitamina D, ergokalciferol (vitamin D2) in holekalciferol (vitamin D3), sta, sicer v relativno majhnih količinah, naravno prisotni v nekaterih živilih. Večino vitamina D3, ki ga človek potrebuje, se endogeno sintetizira v koži iz 7 dehidroholesterola pod vplivom ultravijoličnih B-žarkov (UVB). S pomočjo dveh hidroksilacij se vitamin D sprva preoblikuje v metabolit kalcidiol (25(OH)D), nato pa v hormonsko obliko kalcitriol (1,25(OH)2D), ki predstavlja ligand za receptor vitamina D (VDR). Gre za transkripcijski faktor, ki se veže na mesta v deoksiribonukleinski kislini (DNA), ki so odzivna na vitamin D (VDRE). Obstaja na tisoče teh vezavnih mest, ki na celično specifične načine uravnavajo na stotine genov. Identifikacija receptorja VDR v večini tkiv in celic v telesu ter ugotovitev, da je množico genov mogoče neposredno ali posredno uravnavati z 1,25(OH)2D, kažejo na koristi vitamina D na zdravje ljudi. Vendar pa danes zaradi sodobnega načina življenja živimo v globalnem pomanjkanju vitamina D, ki nima negativnega vpliva samo na skeletni sistem, ampak tudi olajša razvoj in napredovanje več različnih bolezni, vključno s srčno-žilnimi, s sladkorno boleznijo, z avtoimunskimi, respiratornimi, nevrološkimi boleznimi, rakom in drugimi. Kljub naraščajočemu številu opazovalnih študij, randomiziranih kliničnih in drugih raziskav, ki bi podprle različne povezave neskeletnih koristi vitamina D z zdravjem ljudi, metaanalize in sistematični pregledi literature običajno podajajo nedosledne zaključke. Na osnovi pregleda literature in opravljenih študij je bil cilj naloge ugotoviti, v kolikšni meri vitamin D dejansko vpliva na zdravje ljudi in na določene bolezni.

Keywords

vitamini;vitamin D;mehanizem delovanja;hipervitaminoza;pomanjkanje vitamina D;bolezni;vpliv na zdravje;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [E. L. Karara Geršak]
UDC: 612.392.015.6:577.161.2
COBISS: 76500483 Link will open in a new window
Views: 288
Downloads: 55
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Other data

Secondary language: English
Secondary title: Effects of vitamin D on human health
Secondary abstract: Vitamin D is a prohormone that can be photochemically produced in the skin as well as ingested through diet, as a dietary supplement or as a medication. The two main forms of vitamin D, ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3) are, although in small quantities, naturally present in some foods. However, the majority of vitamin D is acquired via the action of sunlight on the skin, converting 7 dehydrocholesterol to vitamin D3. Vitamin D is metabolized first to calcidiol, 25(OH)D, and then to the hormonal form calcitriol, 1,25(OH)2D. Calcitriol is the ligand for the vitamin D receptor (VDR), a transcription factor, that binds to sites in the deoxyribonucleic acid (DNA) called vitamin D response elements (VDREs). There are thousands of these binding sites regulating hundreds of genes in a cell-specific way. The identification of a VDR in most tissues and cells and the observation that a multitude of genes may be directly or indirectly regulated by 1,25(OH)2D have provided a rationale for the health benefits of vitamin D. Due to the modern way of life, we live in a global vitamin D deficiency, which not only negatively affects the skeletal system but also facilitates the development and progression of several different diseases, including cardiovascular diseases, diabetes, autoimmune diseases, respiratory diseases, neurological diseases, cancer among others. Yet, despite the growing number of randomized controlled clinical trials, which could support linking the non-skeletal health benefits of vitamin D, meta-analyses of these studies have drawn inconsistent conclusions. Based on theoretical research of the literature and studies, the aim of this paper is to determine to what extent vitamin D affects human health and certain diseases.
Secondary keywords: vitamins;vitamin D;mechanism of action;hypervitaminosis;vitamin D deficiency;diseases;effects on human health;
Type (COBISS): Bachelor thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo
Pages: IX, 30 f.
ID: 13439772