Please be aware that you should not take coral calcium (it states this on the label) if you have an allergy to shellfish. I am allergic to crab (not lobster, shrimp, etc. just crab). I thought since I am only allergic to crab it would be alright. Ont the contrary, I found that when I took the coral calcium I kept having these "waves" of nausea throughout the day. I always felt like I didn't feel well. I stopped taking it and the nausea is gone. So be aware of this side affect and the allergy warning.