The most abundant elements in the body are hydrogen, oxygen, carbon, and calcium sulfur nitrogen boron

The best answer is nitrogen. After all, it is found in our nucleic acids and proteins. Calcium can be found abundantly in our bones since calcium makes our bones strong. Sulfur can be found in our body but only in low and insignificant amounts. Boron is said to be lethal when taken in great amounts in our body; it can cause diseases and illnesses.