Search

Vitamin D receptors (VDRs) are present in almost all cells of the immune system, including B cells, T cells, NK (Natural Killer) cells, dendritic cells, and monocytes, as well as the epithelial cells of many organs such as the intestine, pancreas, prostate, lungs, and cardiomyocytes. In addition, some immune cells, including dendritic cells, macrophages, and B and T cells, can synthesize calcitriol by expressing 1α-hydroxylase. Upon binding to VDRs, vitamin D (Vit D) regulates the expression of genes involved in immune responses, including those encoding for cytokines. It modulates the production of pro-inflammatory cytokines while promoting the synthesis of anti-inflammatory cytokines. Vit D also affects the differentiation and maturation of cells of the immune system. By inhibiting the nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways, Vit D reduces the expression of pro-inflammatory genes. These effects highlight the potential of Vit D as a therapeutic agent in the management of inflammatory diseases, including autoimmune disorders, cardiovascular diseases, diabetes, metabolic syndrome, cancer, neurological diseases, depression, and inflammatory bowel disease.

In this study, we aimed to reveal the pro-inflammatory effects of serum 25-hydroxyvitamin D3 (Vit D) deficiency and insufficiency in new-onset type 2 diabetes mellitus (T2DM) and prediabetes. We recruited 84 prediabetes patients, 94 new-onset T2DM patients and 113 healthy participants. We measured the levels of C-reactive protein (CRP), fibrinogen, ferritin, interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α), nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) in the serum of the participants. ANOVA Bonferroni and Kruskal-Wallis Dunn tests were used to compare the inflammation markers and vitamin D levels between the groups. Based on covariance analysis with age, gender and BMI, the Vit D levels of the T2DM group were significantly lower ( p < 0.003). Pro-inflammatory markers and CRP were significantly higher in prediabetic and diabetic subjects. In the prediabetes group, IL-1β, IL-6, IL-8, TNF-α and MAPK were significantly higher in those with Vit D insufficiency and deficiency groups. In the T2DM group, IL-1β, IL-6, IL-8, TNF-α, NF-κB, MAPK and CRP were significantly higher in those with Vit D insufficiency and deficiency. Our study emphasizes the pro-inflammatory effects of Vit D deficiency and insufficiency in new-onset type 2 diabetes mellitus and prediabetes.

This study aimed to reveal the perceptions and conspiracy theories surrounding the new coronavirus infection. We aimed to explore associations between COVID-19 conspiracy beliefs with recommended health protective attitudes and sociodemographic features among the Turkish population. A questionnaire consisting of seven items about COVID-19 conspiracy theories and perceptions and ten items about attitudes was given to patients and their relatives in five different centres during the second national lockdown in Istanbul. A chi-square test was used to evaluate the associations of disease perceptions and conspiracy beliefs with sociodemographic features and with health protective attitudes. Logistic regression analysis was performed for significant results. Of 483 participants, 242 (50.1%) were found to have a conspiracy belief. Conspiracy theories were more frequent in the participants who were older than 50 years of age ( p = 0.009) (OR: 1.83) and less frequent in higher education levels ( p = 0.005) (OR: 0.499). In addition, 6.6% of the participants were infected with COVID-19, but having the infection was found to have no effect on disease perceptions or conspiracy beliefs. Wearing a mask in crowds, avoiding shaking hands and kissing, and washing hands were less frequent among conspiracy believers and participants with impaired perceptions. These results indicate that misconceptions and conspiracy beliefs are driving the adoption of disinformation about the prevention of COVID-19 infection.