Phosphorus is needed for healthy teeth, proper bone and cell growth, and helps regulate heart contractions. A deficiency in phosphorus is quite rare for is found in most foods, especially meats, dairy products and junk foods. In combination with calcium, phosphorus is necessary for the formation of bones and teeth and of the nerve cells.
Phosphorus is second to calcium in abundance in the body. It is very widely distributed in both plant and animal foods so it is unlikely that deficiency would be a problem.