1, 25-dihydroxycholecalciferol is recognized as a potent immune-modulator which can fight against the pathogens via the activation of vitamin D3 receptors (VDRs), as well as stimulating various cytokines in infectious diseases. In the present study, because of the vitamin D3 has an appropriate immunomodulatory, the effects of this vitamin on the levels of pre-inflammatory and anti-inflammatory cytokines have been investigated in calves with experimental pasteurellosis. This study was experimentally carried out on 10 Holstein crossbred male calves (2–4 months) that were divided into two groups. Prepared Pasteurella multocida (3 × 10⁹ CFU/mL) was inoculated in the trachea with a lavage catheter and then the treatment group was injected with 1, 25-dihydroxycholecalciferol after confirming pneumonia. Blood sampling, clinical symptoms scoring and radiological evaluation were recorded for both groups at different time intervals. The prescription of, vitamin D₃ to the treatment group caused a decline in clinical symptoms score and changed interstitial and alveolo-interstitial lung pattern to such a degree that it could recover in comparison with the control group.

The concentrations of pro-inflammatory cytokines (i.e., IL-1β, IL-6, and TNF-α) and the chemokine (IL-8) showed a significant decrease in the treatment group while the concentration of IL-10 increased in the treatment groups following the vitamin D₃ injection (P = .001). The evidence from the current study suggests that vitamin D3 exert the immunomodulatory effects in infectious diseases through the regulation of cytokines and activation of VDR pathways to produce antimicrobial peptides.

如图1所示，25-二羟基胆钙化固醇被认为是一种有效的免疫调节剂，可通过激活维生素D3受体（VDR）以及在感染性疾病中刺激各种细胞因子来对抗病原体。在本研究中，由于维生素D3具有适当的免疫调节作用，因此在患有实验性巴氏杆菌病的小牛中研究了该维生素对炎症前和消炎细胞因子水平的影响。这项研究是在10只荷斯坦杂交雄性犊牛（2-4个月）上进行的，分为两组。准备的多杀巴斯德氏菌（3×10 ⁹ 将CFU / mL）用灌洗导管接种在气管中，然后在确认为肺炎后向治疗组注射1，25-二羟基胆钙化固醇。两组均在不同时间间隔记录血样，临床症状评分和影像学评估。与治疗组相比，治疗组服用维生素D ₃导致临床症状评分下降，并且改变了间质和肺泡间质的肺功能，使其恢复。

治疗组中促炎细胞因子（即IL-1β，IL-6和TNF-α）和趋化因子（IL-8）的浓度显着降低，而IL-10的浓度在治疗组中显着降低维生素D ₃注射后的两组（P  = .001）。来自当前研究的证据表明，维生素D3通过调节细胞因子和激活VDR途径以产生抗菌肽，在传染病中发挥免疫调节作用。