Vitamin D, 25D, 24,25D levels from serum of +D mice, before and after 2 wks of A) metronidazole (M) or B) vancomycin (V) or C) +D WT GF mice before and after Abx treatment. Values are the mean ± SEM of n=8 mice per group, 4 males and 4 females (A and B) or (C) n=12 mice per group, n=9 males and n=3 females. C is the pooled data from two independent experiments. Paired t-test was used to test significance. *P<0.05, **P<0.01, ***P<0.001