Vitamin D status is not associated with inflammatory cytokine levels during experimental human endotoxaemia. (3rd January 2013)

• Record Type: Journal Article
• Authors: Kox, M.; van den, M. J. W.; van der, J. G.; Wielders, J. P. M.; van der, A. J.; Pickkers, P.
• Is Part Of: Clinical and experimental immunology. Volume 171:Number 2(2013:Feb.)
• Page Start: 231
• Page End: 236
• Publication Date: 2013-01-03
• Subjects: Immunopathology -- Periodicals; 616.079
• DOI: 10.1111/cei.12006
• Languages: English
• ISSNs: 0009-9104

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>Vitamin D has been shown to modulate innate immune responses <italic>in vitro</italic> and <italic>ex vivo</italic>; however, human <italic>in‐vivo</italic> data are lacking. At high latitudes, seasonal vitamin D deficiency is common due to alternating ultraviolet (UV)‐B radiation exposure. In the present study, we investigated whether levels of 25 hydroxyvitamin D<sub>3</sub> [25(OH)D<sub>3</sub>] and its active metabolite 1, 25 dihydroxyvitamin D<sub>3</sub> [1, 25(OH)<sub>2</sub>D<sub>3</sub>] are subject to seasonal variation and whether plasma levels of these vitamin D metabolites correlate with the <italic>in‐vivo</italic> cytokine response during experimental human endotoxaemia [administration of lipopolysaccharide (LPS) in healthy volunteers]. Plasma levels of 25(OH)D<sub>3</sub> and 1, 25(OH)<sub>2</sub>D<sub>3</sub> were determined in samples obtained just prior to administration of an intravenous bolus of 2 ng/kg LPS (derived from <italic>Escherichia coli</italic> O:113) in 112 healthy male volunteers. In the same subjects, plasma levels of the inflammatory cytokines tumour necrosis factor (TNF)‐α, interleukin (IL)‐6 and IL‐10 were analysed serially after endotoxin administration. Plasma levels of 1, 25(OH)<sub>2</sub>D<sub>3</sub>, but not 25(OH)D<sub>3</sub>, were subject to significant seasonal variation, with lower levels in autumn and winter. 25(OH)D<sub>3</sub> and 1, 25(OH)<sub>2</sub>D<sub>3</sub> levels did not correlate with plasma cytokine responses. Furthermore, 25(OH)D<sub>3</sub> deficient subjects (< 50 nmol/l) displayed an identical cytokine response compared with sufficient subjects. In conclusion, plasma levels of vitamin D are not correlated with the LPS‐induced TNF, IL‐6 and IL‐10 cytokine response in humans <italic>in vivo</italic>. These findings question the direct role of vitamin D in modulation of the innate immune response.</p> </abstract>