How long are vitamins good past the expiration date?

This is a very broad question as it may be similar to comparing bread and dried food when comparing to the most stable vs unstable. The shorter the expiry time, the less long after expiry that it is safe. Creams and liquids can be less stable than medication. It also depends on if they are stored in dry cool places or not.

I am generally conservative about this and following 6 months after expiry, I get suspicious. However, if you can afford a doctor's visit, or even if a pharmacy technician can advise you, I'd say to get a new stock in case.