Fifteen to 20 tablets, taken all at once, will kill a human. If the body does not reject them through vomiting, then they proceed to damage the liver irreparably. Two tablets will kill a headache. This way, they easily exceed the maximum dosage of eight tablets per 24 hours. Vitamin A can poison you.
More vitamins means more health is wrong.
You need just enough vitamins, not an extra dose. Many pharmacists here sell sedatives and other prescription drugs, like antibiotics. One sedative, 'alprazolam', is highly effective as a sleep inducer and anxiety-abater. But a doctor might hesitate to prescribe the drug for more than a few weeks because of its side-effects. It's mildly addictive.