I've been invited to try reliv supp. for my headaches. i am concerned and skeptical about the product. is this safe? are does it provide too much vit?

Might be a scheme: There are many marketing schemes out there, to sell stuff and make money for those companies owners or founders. Many schemes have familiar names, because they advertise a lot. Supplements are not tested like FDA-approved medications are, so nobody really knows the safety or the danger of using a particular brand. Most vitamins can be bought at local stores without paying into a marketing scheme.