Osteopenia and phenylketonuria.

Trabecular bone mineral content was assessed by quantitative computed tomography in eleven young adults with phenylketonuria who had been treated from early childhood with a diet restricted in natural protein and supplemented with amino acids, minerals and vitamins. There was a significant reduction in the bone mineral content of patients compared with the normal population. Prospective studies are indicated in younger patients to ensure optimum bone mineralisation is achieved by adulthood.