Phosphorus is essential for other processes, too, especially for producing collagen to make or repair your tendons, ligaments, cartilage, skin and eyes. (Bones are 75% collagen, by the way.) Without phosphorus, your body can’t generate connective and organ tissue. Also, phosphorus is a key element for using fat soluble vitamins A, D, E, and K.
It’s also a key component in phospholipids (foss-foe-lip-ids), the main component in cell membranes. Phospholipids allow fat- and water-soluble nutrients to pass in and out of cells. Cell membranes would collapse and cells would die without them.