Abstract
To investigate the effects of vitamin D supplementation before pregnancy on the offspring's cognitive function in mice with advanced maternal age (AMA). Thirty-two-week-old female mice were randomly allocated into two groups: the 32 W+VD group (receiving 10 IU/g body weight vitamin D3 dissolved in 200 μl corn oil per day), and the 32 W group (receiving 200 μl corn oil per day) for one week before mating with ten-week-old male mice. Another group of eight-week-old female mice was given 200 μl corn oil for the same period of time and set as normal childbearing age controls (8 W group). The pregnancy outcomes were recorded and the offspring at the age of 6 weeks were subjected to behavioral tests. Finally, the expression level and distribution of neural cell markers in the offspring's hippocampus were detected by immunofluorescence. Mice with AMA had higher risk of adverse pregnancy outcome, smaller litter size, and offspring development. Vitamin D supplementation in mice with AMA promoted offspring development. AMA and maternal vitamin D supplementation before pregnancy did not change the anxiety and depression of young adult offspring. AMA impaired spatial learning and memory function of offspring while vitamin D supplementation before pregnancy rescued the impairment. AMA decreased NEFH (neurofilament protein) and MAP2 (microtubule binding protein) expression in offspring hippocampus, but vitamin D supplementation before pregnancy promoted NEFH and MAP2. Vitamin D supplementation before pregnancy can rescue the impaired learning and memory in offspring born to AMA mice. Our results highlight the significant impact of maternal vitamin D supplementation on the cognitive function of offspring.