Willow
Favorite Answer
They probably lost some of their potency, so if you want the full benefits of a vitamin, it'll be best to purchase a new bottle.
Things that affect potency along with age of the vitamins are:
- Storage conditions; storing it in a hot or humid environment (like bathrooms) degrade them faster.
- Opened versus unopened. Since yours are unopened, they should have more potency than if they had the seal broken.
- Light. If the bottle isn't opaque and lots of light gets inside, then they can lose potency. Most vitamins that are light sensitive are in opaque bottles, but lots are in clear but dark bottles. If they're old, even the dark bottles still allow light in, so over time, potency can decrease.