Abstract
BACKGROUND: This study aimed to explore the effect of vitamin D supplementation on lymphocyte subsets in infertile women. METHODS: The study involved a total of 247 patients who suffered recurrent embryo implantation failure (RIF) or recurrent spontaneous abortion (RSA) between January and December 2019 in the Reproductive Medicine Center of Children's Hospital of Shanxi and Women Health Center of Shanxi. The differences in the vitamin D and lymphocyte subsets of the two diseases, the correlation between the 25-hydroxy vitamin D and lymphocyte subsets, the changes in the lymphocyte subsets after vitamin D supplementation and the impact on pregnancy outcome were analysed. RESULTS: The prevalence of vitamin D deficiency was 77.33% (191/247). After vitamin D supplementation, there were no significant differences in helper T cells (Th), cytotoxic T cells (Tc), Th/Tc and natural killer cells (NK) (p > 0.05), but there were significant differences in leukocyte differentiation antigens 3+ (CD3+), natural killer T cells (NKT), B lymphocytes and vitamin D (p < 0.05). Before vitamin D supplementation, the difference in the composition ratio of different vitamin D levels between the RIF and RSA groups was not statistically significant. At different vitamin D levels, there were no significant differences in CD3+, Th, Tc, Th/Tc, NK or B lymphocyte (p > 0.05), but there was a significant difference in NKT (p < 0.05). CONCLUSION: Vitamin D supplementation can reduce the level of NKT in infertile women, which may be of benefit to the pregnancy outcome of couples who experience RIF.