What determines the expiration date of vitamins?

Question

I've been told that the expiration dates on the bottles of vitamins are of no real value as they are still good for several months after that. If this is true then why bother to put one on them?

Answer 1

If the vitamins are oil (fat) soluable like Vitamin E, the oil can go rancid. If the vitamins are water soluable...theoretically water can get into the pills and break down the vitamins, but if you never open the bottle, what are the chances?

I'm pretty sure most old vitamins don't get thrown away but are instead sent back to the company.

It may also be to keep the inventory circulating that the expiration date is put on. Storing inventory makes it a potential liability.

Answer 2

Why worry about it. If you buy a 60 day supply and get an expiration date of, say, 2 years - you and me don't have to worry about it.