Vitamin A supplementation reduces the Th17-Treg - Related cytokines in obese and non-obese women

Objective: The objective of the present study was to investigate the effect of vitamin A supplementation on serum Th17 (IL-6, IL-17, IFN gamma) and Treg (TGF-beta, IL-10) related cytokines in obese and non-obese women. Subjects and methods: In a randomized double blind placebo controlled design, 56 obese women were randomly assigned to receive either an oral dose of 25,000 IU retinyl palmitate or placebo per day for 4 months. Twenty eight ages matched non-obese women were also received vitamin A. At the study entry, anthropometric variables were measured and serum Th17 and Treg related cytokine profile were determined at baseline and 4 months after intervention. Results: Significantly higher baseline concentrations of IL-6 were observed in obese compared with non-obese women (P < 0.05). However, the initial concentrations of other cytokines were not significantly different between groups. The mean concentrations of IL-17 and TGF-beta were significantly decreased after vitamin A supplementation in non-obese and obese women respectively. Positive relationships between IL-17 and IL-10 (r = 0.42, P < 0.001), TGF-beta and IL-17 (r = 0.35, P < 0.001) and between IL-10 and IFN-gamma (r = 0.41, P = 0.002) in total participants were also observed. Conclusions: The results of the present study showed for the first time that vitamin A supplementation reduces serum concentrations of IL-17 and TGF-gamma in reproductive age women. Further studies are needed to explore the possible underlying mechanisms.