Calcium is the most abundant mineral in the body. It actually accounts for 1.5% of your body weight. A lot of people don't know this but calcium is actually needed for muscle contractions. N2joint RX already has a full dosage of calcium per serving but taking additional calcium won't hurt you or anything like that.
I personally don't consume any dairy products so I use N2joint RX and a calcium supplement each day.
If you don't consume any dairy products either, I would add a dosage of calcium into your supplement stack each day. If you consume a lot of calcium in your regular diet, then adding a calcium supplement isn't needed since N2joint RX has a full calcium supplement included in the supplement AND you are getting a a lot of calcium in your daily diet.