VITAMIN OVERLOAD A RISK, NIH SAYS
Over half of U.S. adults use multivitamins, mostly the pretty healthy people who also eat nutrient-fortified foods. Yet there's little evidence that most of the pills do any good -- and concern that some people may even get a risky vitamin overload, advisers to the government said Wednesday.
Ref. https://www.cnn.com/2006/HEALTH/05/17/diet....s.ap/index.html
I have heard from my doctor that vitamins can be pretty useless depending how you take them. She suggests always taking lower amounts at a time, always use softgels as opposed to hard packed tablets, and never take to much at one time. Vitamin C is one of those vitamins that will just be disposed of if you take too much. She also recommended taking chewables when ever possible because it is less likely to not be absorbed. She has never told me you can take too much, I really think you would have to take allot to cause harm.
I only take one multi-vitamin because I don't eat properly as I should, but I have also read more information like this that went into thoroughl detail about the dangers. Some, thankfully just get metabolised out of the system and are gone, but others are so dangers as to cause organ failure. Anytime I see that something isn't regulated by the FDA, I am wary.