Calcium (macromineral) Calcium (Ca2+) is the most common and abundant mineral in the body. It is needed for the construction of bones and teeth. Calcium plays a significant role in both nervous conduction and muscle contraction. It is also necessary to blood clotting. Calcium is also a common second messenger, and this helps explain why calcium regulation in the body is so important. IRON ( micromineral) The iron as a part of hemoglobin forms a loose association with oxygen, and in this way red blood cells transport oxygen. Iron is enzyme cofactor necessary to cellular metabolism.