Ever since humans discovered fire, our activities have been releasing a "dog's breakfast" of unnatural chemistry. The list has grown to well over 75,000 free elements, compounds and pharmaceuticals. Many of these are acidic, electron-hungry oxidants and free radical generators.
A human study published in the New England Journal of Medicine in 1995 showed that women who consumed 10,000 IU of preformed vitamin A from supplements per day had 4.8 times the rate of birth defects than those who consumed 5,000 IU per day while pregnant. The increased frequency of defects was concentrated among babies born to women who consumed high levels of vitamin A before the seventh week of gestation.
It is a heavily guarded secret within the medical establishment (especially within the corridors of the CDC) that the Cochrane Database Review, which is the gold standard within the evidence-based medical model for assessing the effectiveness of common medical interventions, does not lend unequivocal scientific support to the belief and/or propaganda that flu vaccines are safe and effective.