Folic acid generally has been regarded as a nontoxic vitamin (NRC, 1998). No adverse responses to the ingestion of folic acid have been documented in any species. Fuchs et al. (1995) reported that supplying a shock dose of 30 mg per kg every seven days, which provides much greater levels than the requirement for folic acid, had no negative effect on changes of selected biochemical and hemologic indices in pregnant sows.