[thedoc (OP)]

Cynthia Ho asked the Naked Scientists:
   Why do many vitamin and supplement pills exceed the recommended dietary allowance (RDA), with in certain cases the doses can be 3000% of the RDA? Isn't this a waste of vitamins and minerals as the excess isn't store in the body, but gets excreted?
Many thanks.
What do you think?

[Bored chemist]

Their point is to make money for the manufacturer, seller etc.
There might be a case for some vitamins which are stored if you had a tablet with 7 times the RDA and took it weekly.
But, of course, the best plan is to eat a diet that provides the vitamins you need in a steady supply.

[alancalverd]

There was a suggestion that excess vitamin C would stave off the common cold, but it doesn't.

Excess vitamin A will kill you but will be very difficult to detect.

Excess of other vitamins makes money for the manufacturer.

[Bored chemist]

One of the D vitamins is used as a rat poison; does that count?

[Monox D. I-Fly]

One of the D vitamins is used as a rat poison; does that count?

Which part of it?

Oh wait, maybe I know the answer: The sunlight. Almost never seen a wild rat in broad daylight.

[Bored chemist]

One of the D vitamins is used as a rat poison; does that count?

Which part of it?

Oh wait, maybe I know the answer: The sunlight. Almost never seen a wild rat in broad daylight.

It's not "part of it"
https://en.wikipedia.org/wiki/Cholecalciferol#Use_as_rodenticide
The stuff is seriously toxic if taken in excess.
So, as was pointed out, is vitamin A

[Monox D. I-Fly]

Speaking of rodents, what counts as them? I know mouses and rats count, but do rabbits and hares count? What about squirrels, beavers, hedgehogs, urchins, and porcupines? Also, do hamsters and marmots count?

[Bored chemist]

Speaking of rodents, what counts as them?

https://en.wikipedia.org/wiki/Rodent