Ask the experts
Is it absolutely necessary to get rid of vitamins by the expiration date on the bottle? Or is there a certain amount of time that they can be kept after that date? How long after that date are they still effective?
The expiration date on food and supplements has become an ending point for some and a starting point for others. I have heard many people discuss how much time you have left once you hit the expiration date whereas others get rid of something the day before the expiration date.
The expiration date on vitamins is there for a reason. The date lets you know when the vitamins will no longer be effective. I would not recommend taking them past the expiration date. If you find that your vitamins are expiring before you are able to finish them, you would be better off buying them in smaller quantities. You want to get all of the vitamins and minerals from your supplement, so take them as instructed before they lose their effectiveness.
"General Information and Resources for Dietary Supplements"