Effect of Vitamin D Supplementation on Balance in CKD

Patients with end-stage renal disease on dialysis (ESRD5D) are 4-5x more likely to suffer from a fracture. Fractures can occur spontaneously but typically occur after a fall. Further, 70-90% of patients with ESRD5D are vitamin D deficient. Vitamin D supplementation has become routine care for many in this patient population, but evidence is lacking to support this practice. The proposed projects objective is to gather needed preliminary data regarding the effects of vitamin D supplementation on balance and muscle strength in patients with ESRD5D.

In 2009, ~6% of the annual Medicare budget was spent to treat people with end-stage renal disease on dialysis (ESRD5D), making chronic kidney disease (CKD) an important and costly health problem affecting the United States. These patients are 4-5x more likely to suffer from a fracture. Fractures can occur spontaneously but typically occur after a fall. Further, 70-90% of patients with ESRD5D are vitamin D deficient. Vitamin D supplementation has become routine care for many in this patient population; without evidence to support this practice. While studies on the elderly document the effect of vitamin D in decreasing fall risk, findings are inconclusive for those elderly individuals with ESRD5D. The proposed projects objective is to gather needed preliminary data regarding the effects of vitamin D supplementation on balance and muscle strength in patients with ESRD5D. Thirty patients with ESRD5D will be recruited and randomized into two groups: 1) 4000 or 2) 800 IU oral, vitamin D taken daily. Men and women (ages 21-70 years) will be recruited from among patients receiving hemodialysis at a UNMC-directed dialysis facility. Other inclusion criteria include 1) likely to be able to complete the study; 2) ambulatory, without a walking aid; 3) able to complete questionnaires interactively with a research nurse; and 4) greater than 3 months on hemodialysis. Exclusion criteria include patients on peritoneal dialysis, allergy to vitamin D, liver disease, intestinal disorders that would interfere with vitamin D absorption; vitamin D supplements >800 IU per day, glucocorticoids, anticonvulsants, drug therapies for osteoporosis. All patients will be receiving standard of care per their nephrologist. Functional data will be collected at baseline, three, and six months. Data collected will include balance, muscle strength, and falls. Data to monitor vitamin D levels and calcium will be pulled from their medical record. There is no follow up after the six month long study.

This measures fall risk. The measure is a length of time it takes to complete a walking test. A longer score indicates a longer amount of time to complete the test. A shorter amount of time is considered better.

This 10 item assessment measures one's balance. Scores can range between 0-40. A score of 40 is considered the best performance.

Walking speed is measured over distance of 20 meters. Walking speed is measured in meters per second. A faster walking speed is considered better. Time in seconds needed to cover 20 meters while walking is reported.

Muscle strength of the muscles in the thigh will be measured using an isokinetic dynamometer. Strength is measured by the amount of force (peak torque) and will be divided by body mass (kg). Strength is reported as a percent of body weight. A greater peak torque percentage is considered better.

Inclusion Criteria: must be likely to be able to complete the study must be able to walk without a walking aid must be able to complete questionnaires interactively research staff must have been on dialysis for greater than 3 months all patients must be receiving standard of care per their nephrologist Exclusion Criteria: peritoneal dialysis an allergy to vitamin D liver disease intestinal disorders that would interfere with vitamin D absorption taking vitamin D supplements >800 IU per day, glucocorticoids, anticonvulsants, or other drug therapies for osteoporosis are pregnant