When storing vitamins, you want to make sure they're in a cool, dry place away from heat or humidity. So a lot of people store their vitamins in a medicine cabinet, but actually that's not the ideal place because in a bathroom, there's a lot of moisture from the sink and the shower. The best place is actually somewhere like the bedroom, where there are no fluctuations in the humidity, or maybe a dry pantry away from the kitchen. If vitamins soften or start to develop dark spots, it's best not to take them because this means they're probably breaking down and have also lost their potency. You probably know this already, but a reminder not to take vitamins on an empty stomach, that way you avoid feeling nauseous. As well, just make sure to keep vitamins and supplements out of reach and away from small children.