Vitamin D<sub>3</sub>Supplementation Promotes Regulatory T-Cells to Maintain Immune Homeostasis After Surgery for Early Stages of Colorectal Cancer
PATNAPA SRICHOMCHEY, Sophida Sukprasert, NATHAPONG KHULASITTIJINDA, Narin Voravud, Chucheep Sahakitrungruang, Putthapoom Lumjiaktase
Abstract
<h3>Abstract</h3> Background/Aim: Vitamin D<sub>3</sub> (VD<sub>3</sub>) affects the regulation of the immune system, including the differentiation and function of regulatory T-cells (Tregs). Tregs play an important role in maintaining immune homeostasis in patients with colorectal cancer (CRC). The effects of VD<sub>3</sub> on Treg-associated immune function were investigated in Thai patients in the early stages of CRC. Materials and Methods: Twenty-eight patients were randomized to one of two groups: Untreated or treatment with VD<sub>3</sub> for 3 months. Whole blood samples were collected at baseline, and at 1 and 3 months. Peripheral blood mononuclear cells were isolated and the populations of forkhead box P3-positive Treg cells was analyzed by flow cytometry. The levels of Treg-associated cytokines, interleukin 10 (IL-10) and transforming growth factor beta 1 (TGF-β1), were measured by enzyme-linked immunosorbent assays. Results: Serum VD<sub>3</sub> levels of the VD<sub>3</sub>-treated group were significantly increased at 1 (p=0.017) and 3 months (p<0.001) compared to the untreated control group. The mean percentage of Tregs was maintained between 1 and 3 months in the VD<sub>3</sub>-treated group. At 3 months, the untreated group had significantly lower Treg levels than the VD<sub>3</sub>-treated group (p=0.043). Serum IL-10 levels of the VD<sub>3</sub>-treated group were statistically increased at 1 month compared to the control group (p=0.032). No significant difference in serum TGF-β1 levels was observed between the two groups. However, the TGF-β1 level in the VD<sub>3</sub>-treated group at 1 month was lower than that of the control. Conclusion: Our findings suggest that VD<sub>3</sub> supplementation can maintain immune responses in the early stages of CRC, helping to control Treg function. Therefore, VD<sub>3</sub> should be supplemented to maintain immune homeostasis, especially in patients with vitamin D deficiency.