What it is: A MINERAL as essential to the body as CALCIUM or IRON. Between 80 and 90 percent of the body's phosphorus is concentrated in the bones and teeth, usually in the form of CALCIUM PHOSPHATE. More of it, as PHOSPHORIC ACID, is present in DNA, in RNA, in all cells; indeed, cells can't form or grow without it. In addition, many enzymes and B VITAMINS need it to function, and it's key to the metabolism of CARBOHYDRATES, FAT and PROTEINS. Finally, phosphorus helps shuttle fats through the bloodstream and move nutrients in and out of cells.