What is the potential importance of taking phosphorus?

Phosphorus is a necessary nutrient, but diets are almost always adequate in this mineral. Some authorities have suggested that excess intake of phosphorus is hazardous to normal calcium and bone metabolism. However, this idea has been challanged. In any case, for most people there does not seem to be a need for phosphorus supplementation. For this reason, many multivitamin-mineral supplements do not contain phosphorus. The only exception is for elderly people, whose diets tend to be lower in phosphorus. Calcium interferes with phosphorus absorption, so older people who are taking a calcium supplement might benefit from taking additional phosphorus.