The Role of Vitamin D3 in Inflammatory Bowel Diseases

Abstract

Vitamin D3, combined with its nuclear receptor, regulates more than 900 genes, which is the reason why its effect is pleiotropic. Among other effects, it influences the immunological system. Its deficit may be one of the environmental factors taking part in the development of auto-immunological diseases. The studies reveal that, among others things, inflammatory bowel diseases occur in higher latitudes, with lower exposure to solar radiation and with decreased production of vitamin D3 in the skin. Patients with inflammatory bowel disease have vitamin D3 deficiency more frequently. The application of vitamin D3, especially among adults with inflammatory bowel diseases, positively influences bone turnover markers and mostly due to its influence on immunological processes, vitamin D3 may be useful in the treatment of the primary health condition. It is necessary to determine the dosage range, as well as the optimal level of vitamin D3 metabolite-25OHD3, where the immunosuppressant effect is the best, with no toxic effects. The basic function of vitamin D3 in the body is its influence on keeping the homeostasis of calcium metabolism, preventing the appearance of rickets, osteomalacia and osteoporosis [1,2]. Vitamin D comes from food -ergocalciferol (vitamin D2), and mostly it is synthesized in the skin under the influence of ultraviolet radiation B (UVB) -cholecalciferol (vitamin D3). Next, in the liver, it is hydroxylated into its inactive form 25 OH D3 (calcidiol) and in the kidney into its active form -1,25 (OH)2 D3--calcitriol. Except for the cells of cuticle of proximal tubule in the kidney, the activity of 1-alfa-hydroxylase have also, among others, antigen presenting cells (APCs), parasympathetic ganglions, hair follicles, cerebral cortex cells, pancreatic islets [3]. Vitamin D acts through its receptors (vitamin D receptors -VDr), which may be found in the majority of organs: in the alimentary tract, bones, the brain, the chest, muscles and others. [3]. Vitamin D combined with the receptor is the regulator of more than 900 genes. In this way it regulates, among others, the calcium metabolism, intestinal calcium transport, as well as cell proliferation and differentiation [4]. An analysis of microarrays and the genome screening of vitamin D3 receptors (VDrs), which are nucleus receptors and direct transcription factors, detected the molecular base of physiological effects of vitamin D3-both its influence on calcium metabolism, immunological system as well as its antitumor activity [4].

Vitamin D3 – a fundamental component of human health and a potential supplement for COVID-19 prevention and therapy

“…Witamina D3, zarówno ta pochodzenia endogennegocholekalcyferol, jak i ta uzyskiwana z produktów spożywczych -ergokalcyferol, są biologicznie nieaktywne [5,13,26]. Do uzyskania biodostępności witaminy D3 dla organizmu wymagana jest jej aktywacja w wątrobie i nerkach [27].…”

“…Cholekalcyferol jest katalizowany przez 25-hydroksylazę do utworzenia 25-hydroksycholekalcyferolu przede wszystkim w wątrobie i wielu innych organach (m.in. w jelicie, mózgu, łożysku) [18,26,32]. W reakcjach tych pośredniczy głównie mikrosomalny enzym CYP2R1, który charakteryzuje się najwyższym powinowactwem do substratu.…”

“…Oprócz tego aktywność 1-alfa-hydroksylazy demonstrują m.in. : melanocyty, komórki immunokompetentne, zwoje przywspółczulne, mieszki włosowe oraz wysepki trzustkowe [3,26]. Wartość stężenia kalcytriolu w surowicy kształtuje się w zakresie od 75 pmol/l do 200 pmol/l; z okresem półtrwania wynoszącym średnio 10-24 godziny.…”

“…VDR jest konserwatywnym białkiem o masie 48,3 kDa, które jest eksprymowane w ponad 38 typach ludzkich komórek, w tym w niemal wszystkich narządach, m.in. w mieszkach włosowych, mięśniach, szpiku kostnym, przewodzie pokarmowym, a także w mózgu [26,28,[41][42][43]. Kalcytriol oddziałuje z receptorem za pośrednictwem dwóch szlaków -tzw.…”

The role of vitamin D in reducing gastrointestinal disease risk and assessment of individual dietary intake needs: Focus on genetic and genomic technologies

“…There is also reason to believe that adequate vitamin D status modulates gastrointestinal inflammation in both forms of IBD, and is likely to prevent these from progressing to CRC . Especially for adults with IBD, vitamin D3 has been suggested to be useful for disease therapy . Because of concerns about possible adverse effects of high doses, especially in relation to hypercalcemic effects, studies are now focusing on vitamin D3 analogs.…”