I noticed that my Rep-Cal Calcium powder has an expiration date on the back. Is this Rep-Cal's way of getting me to buy more calcium when my container is still half full or does the powder actually degrade over time? Thanks for your replies!
If you're using the kind that is only calcium and does not have any vitamins in it, a shelf life of 5 years is totally fine -- that's how long we keep calcium carbonate on our shelves in my biochem lab before buying a new product, and I work with animals daily. Technically after 5 years you wouldn't have to get rid of it, but since you work with animals, it's not worth taking a chance of something being wrong with it (e.g. germs lurking -- anything that has been opened is subjected to them over time) If you are using the kind with vitamin supplements mixed in, I would stick to the recommended expiration, as vitamins can either be included in a metabolically active form, or a pre-metabolic form, and typically have lower shelf life.