Cholecalciferol Supplementation in Kidney Failure Study: Effect on Quality of Life and Muscle Strength

INTERVENTION: Opaque capsule of oral Cholecalciferol 50000units/capsule given weekly for 12 weeks, followed by blinded calcidiol level and dose adjustment based on an algorithm designed to maintain blood calcidiol levels between 80‐175nmol/l. Further blinded calcidiol level and dosage adjustment (if necessary) will occur at 24 weeks, with therapy continuing for 52 weeks. To avoid inadvertant unblinding, the number of capsules prescribed will be capped at 3 per week. CONDITION: Muscle weakness in patients with kidney failure Quality of Life in patients with kidney failure PRIMARY OUTCOME: Hand grip strength measured using a Smedley hand dynanometer (Sportstek, Victoria, Australia). Subjects will attempt 3 maximal contrations on each side, in a seated position with the arm hanging by the side and the forearm flexed to 90 degrees and the writst in neutral postition. The best recorded force on each side will be recorded as well s the presence of a current arteriovenous fistula or loop and the handedness of the subject. Quality of Life, as assessed by completion of the KDQOL‐SF version 1.3 instument. (Kidney Diseases Quality of Life Short Form version 1.3) SECONDARY OUTCOME: Serum calcium. This will be assess monthly, as a categorical variable dichotomised as albumin adjusted levels above or less than 2.55mmol/l, with between group comparison using Fisher Exact Test. All Calcium levels greater than 2.55 will be confirmed using measurement of whole blood ionised calcium. serum alkaline phosphatase using the Architect commercial laboratory testing platform serum phosphate. This will be assessed monthly with levels dichotomised as avove, or less than 1.5mmol/l and between group differences assessed by the Fisher Exact Test. Levels will also be assessed as a mean of the monthly recordings over 12 month, and between group comparison by Student t‐test. troponin positive acute coronary syndrome episodes. This will be assessed using a standard commercial Troponin I assay. An acute coronary event will be deemed to have occured if there is a consistent clinical presentation with troponin I level recorded as >0.03microgram/liter. INCLUSION CRITERIA: Undergoing maintenance therapy with twice or thrice weekly conventional haemodialysis or receiving peritoneal dialysis. Clinically stable.