[Effect of 1 alpha-hydroxycholecalciferol and various dietary phosphorus levels on phosphorus and calcium metabolic indices in rats during hypokinesia].

The exposure of rats to hypokinesia and a phosphorus-enriched diet (Ca : P = 1:3) was accompanied by hypocalciemia, hyperphosphatemia, calcium losses from bones and formation of calcificates in the kidneys. The decrease of the phosphorus content in the diet (Ca : P = 1:0.5--1:1) prevented these disorders. The administration of 1 alpha OHD3 at a dose of 0.025 microgram/day arrested hypokinesia-associated hypocalciemia and bone changes. The administration of 1 alpha OHD3 together with a high phosphorus consumption enhanced nephrolithiasis and induced aortal mediacalcinosis in hypokinetic rats. These data indicate that phosphorus consumption should be reduced in order to prevent disorders in phosphorus-calcium metabolism during hypokinesia. They also suggest that administration of 1 alpha OHD3 may be hazardous in case of excessive phosphorus consumption.