<P> Individuals with phenylketonuria (PKU) must keep their intake of phenylalanine extremely low to prevent a mental disability and other metabolic complications . </P> <P> Maple syrup urine disease is associated with genetic anomalies in the metabolism of branched - chain amino acids (BCAAs). They have high blood levels of BCAAs and must severely restrict their intake of BCAAs in order to prevent mental retardation and death . </P> <P> The body is unable to store excess protein . Dietary protein is converted to individual amino acids by the digestive process, which are then absorbed . When amino acids are in excess of needs the liver takes up the amino acids and subjects them to deanimation, a process that converts the nitrogen from the amino acids into ammonia, further processed in the liver into urea via the urea cycle . Excretion of urea is performed by the kidneys . Other parts of the amino acid molecules can be converted into glucose and used for fuel . When food protein intake is periodically high or low, the body tries to keep protein levels at an equilibrium by using the "labile protein reserve" to compensate for daily variations in protein intake . However, unlike body fat as a reserve for future caloric needs, there is no protein storage for future needs . </P> <P> Research has supported a theory that excessive intake of protein increases calcium excretion in urine, occurring to compensate for the pH imbalance from oxidation of sulfur amino acids . The research is inconclusive as to whether this calcium excretion from bone resorption contributes to osteoporosis . A regular intake of calcium stabilizes this loss . But then another issue arising from over-consumption of protein is a higher risk of kidney stone formation from calcium in the renal circulatory system . </P>

What is the fate of excess intake of dietary protein