Effects of Vitamin D Supplementation on Serum Levels and Gene Expression of IL-10 and IL-35 Among Women with Unexplained Recurrent Spontaneous Abortion.

Abstract

Introduction: The study aimed to investigate the effect of vitamin D (Vit D) supplementation on serum levels and gene expression of interleukin-10 (IL-10) and IL-35 in women with unexplained recurrent spontaneous abortion (uRSA).

Methods: In the current prospective quasi-experimental study, 32 women with uRSA and 32 healthy women with at least one live birth were studied. Peripheral blood samples were collected before and after 12 weeks of daily Vit D supplementation at 1000 IU/day. ELISA was used to measure serum levels of Vit D, IL-10, and IL-35, and gene expression of IL-10 and IL-35 was assessed by PCR at the desired time points. Statistical analyses were performed using SPSSv 22.

Results: Vit D supplementation had no statistically significant effect on serum IL-10 levels (p = 0.176), and no significant differences were observed in the remaining serum comparisons (all p > 0.05). Regarding IL-35, gene expression levels in women with uRSA did not demonstrate a statistically significant within-group change following supplementation (p > 0.05). At baseline, IL-35 gene expression in the control group was significantly higher than in the patient group (p <0.0001), and this difference was also significant after supplementation (p =0.0006).

Discussion: Vit D can potentially regulate the immune system, especially by increasing IL-35, although it has minimal effect on IL-10. The current study had a small sample size and a short supplementation period. Larger and Long-term studies are needed to confirm these results.

Conclusion: Vit D supplementation was linked to changes in IL-35 gene expression in women with uRSA. However, since there were no significant alterations in serum cytokine levels, these findings do not confirm a definitive role for Vit D in enhancing immune tolerance.