Effect of vitamin D replacement in patients with chronic kidney disease

Vitamin D deficiency is common in patients with chronic kidney disease and has been associated with increased risk of heart disease and death. Correcting vitamin D deficiency may improve risk for heart disease through its effects on blood vessel, immune and bone cell function. Stiffness of the arteries (arterial stiffness) is associated with increased risk of heart disease and can be measured using simple non-invasive methods. The effect of vitamin D replacement on arterial stiffness has not previously been studied in patients with kidney disease. This study will examine the effect of vitamin D, a commonly used over-the-counter medication, compared with placebo (“dummy tablet”) on blood vessel function in people with moderate to severe chronic kidney disease who are vitamin D deficient. In this study, you will be randomly assigned (”like flipping a coin”) to take either vitamin D or placebo (1 tablet monthly) for 6 months. If at 3 months, your vitamin D levels remain low, you may need to take the study medications every 2 weeks till the end of the study. Both the vitamin D and placebo medication will be supplied by a specialist compounding pharmacy with a state of the art compounding laboratory and is accredited by the Pharmacy Guild of Australia as a quality care pharmacy and as such operates under a quality care program. If you enter the full study, you will have blood tests and blood vessel function studies before you start and after you complete the study medication. During the study, you will not know which treatment you are on. Your other medications will remain constant. The study requires you to attend the Research Unit at Sir Charles Gairdner Hospital 4 times over a 6-month period.