Ninety children with varying renal diseases were under observation. The investigations conducted have shown that disorders in phosphoric-calcium metabolism depend on the type, activity of chronic glomerulonephritis (CGN) and etiology of chronic renal insufficiency (CRI). Significant disorders in phosphoric-calcium metabolism were detected in patients with nephrotic and mixed types of CGN. Most manifest clinical and x-ray changes of the osseous system were observed in patients with CRI that developed as a result of the tubulointerstitial pathologic process. Low-phosphate diets with preset amounts of Ca and P were developed, composed of products with relatively low content of P, and of new dietetic products rich in Ca. The diets were used for correction of hyperphosphatemia in children with CGN and in those with CRI, simultaneously with drug therapy, to prevent or diminish disorders in phosphoric-calcium metabolism, and to reduce the risk of invalidism among children with chronic renal diseases.