Rats on diets high in phosphorous and low in calcium.

Abstract

It has been reported by a number of investigators 1 , 2 , 3 that rats become rachitic on diets high in P and low in Ca.

Two rats were kept on a normal diet (A) containing 302 mg. P and 414 mg. Ca per 100 gm. diet. Another group of two were given a diet (B) low in P (124 mg. P and 372 mg. Ca per 100 gm. diet). A third group of two were given a diet (C) containing 1044 mg. P and 19 mg. Ca per 100 gm. diet. After three weeks the rats were photographed by X-rays and ashed. The ash was analyzed for Ca, P and Mg. The X-ray photograph showed that the bones of the rats on low Ca, high P were normal, except for a slight osteoporosis. In marked contrast to those on normal diet and diet low in Ca, both rats which received diet (B) became rachitic.

The percentages of Ca and P in the ash of those on diet C were slightly less than in normal rats () of their own age. The P/Ca ratio in the ash of the rats was normal (0.72). The rachitic index figured by McClendon's formula 4 was (A) 5.2, (B) 1.4, and (C) 2.0.