We have always bought Flintstones Complete Vitamins for our son and never had a problem with them. Until recent. The vitamins were not too be expired for another year, and yet, they seemed to have been past expired. They started having strong stinky smells and got black spots. I researched it online and others had the same problem too and was told that it was just too much air had gotten to them and it was harmless. We kept on using them, thinking it wasn't too big of a deal...until I noticed the vitamins were beginning to develop a liquidy substance in and around them. That was my sign to not give them to him anymore. I contacted the Bayer company (Who these vitamins are through) and they sent their apologies along with a coupon for free vitamins. They also requested that I sent in the leftover vitamins in their container, so they can test them and see what was happening. Paid postage and all so that was nice. By the time I got that package to send them in, the vitamins were completely black and smelly. Might be from too much air, since I had to pull them out of the garbage! Thankfully I had just changed it so they weren't with anything else. But still, a vitamin turning black is just weird to me..They told me they will let me know what they find!