What brand are your supplements from? Repcal's d3 has an expiration date labled on it, so does the herptivite. I don't think their calcium expires though because I cannot find an expiration date on them.
plain calcium powder, being a mineral, does not really expire
vitamins (including the previtamin D) DO loose potency /efficacy and should not be used past the expiry date (its not like its expensive to replace anyways)