Our dry cat food is formulated to meet all life stages, from a kitten, adult, and senior ages. The phosphorus levels are .29 grams per oz. and magnesium level is .17%, on an as fed basis, which is in accordance with AAFCO guidelines for feline nutrition. This diet is formulated for healthy cats and is not intended for cats with specific dietary restrictions. If your cat is on a restricted diet, consult your veterinarian to discuss if these levels meet their specific needs.