Effect of vitamin D supplementation during pregnancy on the Th1/Th2 cell balance of rat offspring.

ABSTRACT

Vitamin D has important functions in the immune system, and it may suppress the proliferation of T helper (Th) cells and modulate their cytokine production. In this study, we aimed to investigate the effects of maternal supplementation with different doses of vitamin D on the allergy status of the offspring. We gave pregnant female rats a low dose (48000IU/kg, equal to 800IU/d in human) and a high dose (240000IU/kg,equal to 4000IU/d in human) of vitamin D3 intramuscular injection on gestation day (GD)17, and we used an enzyme-linked immunosorbent assay (ELISA) to determine the levels of immune responsive cytokines including IL-4, IgE, and interferon gamma (IFN-gamma) in the offspring. On postnatal day (PND) 21, plasma IL-4 levels were elevated by 10.43% (p < 0.01) in the offspring from the high dose vitamin D3 group compared with the control group. And offspring plasma IL-4 levels in the low dose group decreased by 7.27% (p < 0.05) compared with the control dose group. We found that the offspring of mothers given a low dose of vitamin D3 had a 6.17% (p < 0.01) decrease in their plasma IgE levels compared to control animals, but the high dose of vitamin D3 showed no effect. The serum 25(OH)D3 levels were negatively correlated with the IL-4 (r = -0.561, p < 0.01) and IgE (r = -0.421, p < 0.05) levels of the offspring from the low dose group. In the lung tissues of the offspring of the high dose group, we observed thickening of the alveolar septa and more inflammatory cells compared with the control group and low dose group. Thickened alveolar septa were also found in the lung tissues of the offspring from the control group. We conclude that high dose vitamin D3 maternal supplementation during pregnancy induced an imbalance of Th1 and Th2 cells in their offspring resulting allergic and inflammatory response.