Objective   To investigate the effect of VA supplement with a different dosage on oxidative DNA daaTage and Oe-MeG adduct in rats.

  Methods   Wistar rats selected for VA supplement trial, were randomly divided into four groups.The first group was no VA supplement as a control, and UTe second, third, forth groups were daily supplemented with 11.43, 42.863, 142.863μgRE(Retinol Equivalent)/(kg^°d)respectively.DNA oxidative damage in the four groups were detected by single-cell gel electrophoresis(SCGE)and Oe-Methyl-guanine(O⁶-MeG)was measured by high performance capillary zone electrophoresis.

  Results   The result of DNA damage showed that intrinsic damage of DNA was more severe in the group of vitamin A deficiency than the groups supplemented with vitamin A(P < 0.01).The lowest damage of oxidative DNA damage reduced by H₂O₂ was found in 42.863μg RE/(kg^°d)group(P < 0.01).O⁶-MeG level in the group of vitamin A deficiency increased significantly chaperonage extending of the supplement deficiency(P < 0.01).O⁶-MeG level was not nearly change in 42.863μg RE/(kg^°d)group in the period of trial.In 142.863μg RE/(kg^°d)group O⁶-MeG level which was significantly higher than deficiency and other two groups in the end of the trial, which was 1.38 times in the first (P < 0.05), 3.57 times in the second(P < 0.01)and 11.75 times in the third groups respectively(P < 0.01).

  Conclusion   If retinol deaciency for a long time can cause or promote DNA damage.Overake retinol did not pretect DNA damage and could produce a strong poisoning effect.A moderate amount such as 42.863μg RE/(kg^°d)could enhance the ability of antioxidation and mitigating DNA damage.