Serum Calcium and Phosphorus Homeostasis in Patients with Chronic Renal Failure at Usman Danfodiyo University Teaching Hospital, North West Nigeria

Mineral metabolism disorders including hypocalcaemia, hyperphosphataemia, and secondary hyperparathyroidism are hallmark complications of chronic renal failure and contribute significantly to cardiovascular morbidity and mortality in affected patients. This study assessed serum calcium and phosphorus homeostasis in chronic renal failure patients at Usmanu Danfodiyo University Teaching Hospital, Sokoto, North West Nigeria. A cross-sectional study was conducted among 120 patients with confirmed chronic renal failure and 60 age-matched healthy controls. Fasting serum total calcium and ionised calcium were measured by colorimetric and ion-selective electrode methods respectively. Serum phosphorus was determined by colorimetric method. Intact parathyroid hormone was assayed by ELISA. Estimated glomerular filtration rate was calculated from serum creatinine. Hypocalcaemia was present in 52.5% of CRF patients and hyperphosphataemia in 64.2%. Elevated PTH was found in 73.3% of cases. The calcium-phosphorus product exceeded 55 mg2/dL2, indicating elevated vascular calcification risk, in 37.5% of patients. Severity of mineral imbalances correlated inversely with eGFR decline. Patients on maintenance haemodialysis showed more severe disturbances than predialysis patients. The study recommends routine monitoring of serum calcium, phosphorus, and PTH at all stages of CRF, early initiation of phosphate binders and calcium supplementation where indicated, and dietary counselling on phosphorus restriction as standard components of CRF management in North West Nigeria. Keywords: chronic renal failure, calcium, phosphorus, parathyroid hormone, mineral metabolism