Effect of protein and phosphate restricted and calcium and alphacalcidol supplemented diet on renal and parathyroid functions and protein status in chronic renal failure patients.

OBJECTIVE: To assess the effect of low protein (0.6 g/kg/day), low phosphate (5-10 mg/kg/day) diet with calcium (600 mg/day) and alpha-D3 (0.5 microgram/day) supplementation on renal and parathyroid functions in patients with chronic renal failure (CRF). METHODS: The study included 20 adult patients of CRF, maintained on diet therapy alone. The patients were followed up for renal and parathyroid functions and protein status for 6 months at monthly interval. RESULTS: There was symptomatic improvement in 88% patients. Blood urea and serum creatinine decreased significantly (p < 0.001 and < 0.01, respectively) and the slope of inverse serum creatinine against time changed to static or an upslope. Glomerular filtration rate (GFR) improved from a basal value of 29.35 +/- 18.2 ml/min to 39.25 +/- 27 ml/min after 6 months. Serum parathyroid hormone (PTH) level of 197.65 +/- 133.7 pg/ml and post treatment level of 254.55 +/- 217.19 after 6 months were not different (p > 0.05). Serum calcium remained stationary with a slight increase in serum phosphorus. Phosphorus had a negative correlation with calcium and GFR, whereas calcium had a negative correlation with PTH and phosphorus. PTH had a positive correlation with phosphorus and negative with GFR and calcium. CONCLUSION: There was an improvement in renal functions without any deleterious effect on the protein status of the patients of CRF. Also, there was halting of parathyroid dysfunction especially in those patients where there was no evidence of pre-existing hyperparathyroidism. Hence, dietry management should be strictly enforced in CRF patients early in the course of disease.