The body contains 100 mg. 1/4 in the muscles, 1/4 in brain, liver, and blood; the rest is in the bones, kidneys, and other tissues. The primary function is to serve as a constituent of enzymes. Catalyze the formation of hemoglobin, help make callagen, assists in wounds healing, and maintains sheaths around nerve fibers.
Important also in helping the cells utilize iron. Also needed in many reactions for respiration and metabolism.