Although there is considerable evidence of the importance of calcium, phosphorus and magnesium in the chemical processes in voluntary muscle, no adequate studies of the metabolism of these substances in patients with muscular disease have heretofore been made. In the present investigation the metabolism of these minerals was studied in 4 patients. There were 2 patients with progressive muscular dystrophy, 1 with myotonia atrophica and 1 with familial periodic paralysis. In addition, the metabolism of calcium and phosphorus was investigated in another patient with myotonia atrophica, but the studies were not as extensive. Since the findings are in essential agreement with those on the other patient with this condition, they are not included in this report.
METHODS
The patients were kept in a special metabolism ward where careful collections of urine and feces could be made and where the diets were rigorously supervised. The mineral balance, for different levels of