EFFECT OF PHOSPHATE SUPPLEMENTATION DURING IMMOBILIZATION OF NORMAL MEN

The effect of oral inorganic phosphate supplements (1 to 2 Gm. phosphatephosphorus daily) on calcium metabolism during immobilization was assessed in six healthy volunteer subjects who were placed in plaster spica body casts for 40 days. Compared to values during the control phase, those subjects who did not receive phosphate supplements showed an increased urinary excretion of calcium, negative calcium balance (averaging -152 mg./day/subject), and calcium oxalate crystalluria. In contrast, subjects who received the phosphate supplement showed a decreased urinary excretion of calcium, a lesser degree of negative calcium balance (mean -78 mg./day/subject, and no crystalluria. In addition, the hypercalciuria and crystalluria which occurred in subjects who initially did not receive a phosphate supplement were reversed when the supplement was begun. The data suggest that phosphate supplements can prevent or ameliorate the hypercalciuria, crystalluria, and negative calcium balance associated with immobilization. © 1969.