Vitamin D and Arteriovenous Fistulae
Vitamin D and Arteriovenous Fistulae
Patients requiring hemodialysis following kidney failure need a form of dialysis vascular
 access in order to undergo the dialysis procedure. Dialysis vascular access dysfunction is an
 enormous clinical problem. While the best form of vascular access is the arteriovenous
 fistula (AVF), its primary problem is early, aggressive cellular ingrowth that leads to poor
 maturation of the vessel, preventing its use for dialysis. Strategies to prevent AVF failure
 are needed.

 Vitamin D is a hormone present in all human bodies and is important for good bone formation
 and immune function. There is new information that links vitamin D to the function of our
 veins and arteries, which are used in the creation of an arteriovenous fistulae. Our bodies
 can make vitamin D and can also get vitamin D from our diet. However, a majority of patients
 with chronic kidney disease and end-stage renal disease (ESRD) have low vitamin D levels
 (vitamin D deficiency). There are several benefits to correcting low vitamin D levels,
 however, it is not know whether correcting low vitamin D in the body will lead to better
 function of the vein and artery used for arteriovenous fistulae creation. The main goal of
 this pilot study is to examine the role of vitamin D supplementation on AVF maturation and
 useability for dialysis. Study results will be used to develop larger studies to examine the
 specific effect that vitamin D supplementation has on the vessels used for AVF creation and
 whether vitamin D promotes AVF maturation.
Hemodialysis vascular access dysfunction is a major source of morbidity and cost among ESRD
 patients, accounting for up to 25% of all hospital stays, and 50% of all costs within the
 first year of initiating dialysis.The AVF provides higher blood flow rates, fewer thrombotic
 and infectious complications, and lower morbidity and cost compared with prosthetic grafts or
 central venous catheters.However,up to 50% of newly created AVF's fail to mature sufficiently
 for chronic hemodialysis use. Clearly, determining factors predictive of poor AVF maturation
 are important from both patient care and health policy perspectives and are worthy of
 investigation.

 Vitamin D has antiproliferative, antioxidant and antiangiogenic properties. The observed
 association of vitamin D deficiency and increased risk of cardiovascular and peripheral
 vascular disease may extend to the vasculature used in the creation of an AVF.

 As renal function worsens, patients with chronic kidney disease (CKD) produce less vitamin D,
 due to impaired renal conversion of 25-hydroxy- to 1,25-dihydroxyvitamin D by declining renal
 1-alpha hydroxylase. As a result, at the time of dialysis initiation,78%-90% of ESRD patients
 are vitamin D deficient. Until recently, vitamin D deficiency among CKD and ESRD patients was
 only treated if hyperparathyroidism was present, however, more attention is now paid to
 nutritional vitamin D deficiency given its association with a range of comorbid
 conditions.Furthermore, 1,25-dihydroxyvitamin D and its analogue compounds are associated
 with improved survival in the CKD and ESRD populations. We believe that the observed benefits
 of vitamin D may improve AVF maturation among a population in which vitamin D deficiency is
 highly prevalent.
Inclusion Criteria

 -  Patients with patients with end-stage renal disease (ESRD) who are suitable candidates
 for AVF creation (as assessed by pre-operative vein mapping) and plan to undergo AVF
 creation are eligible to participate

 -  Study subjects must agree to participate in the study and provide written informed
 consent

 -  Age: Study subjects must be > 18 years old

 -  Sites: Emory University affiliated hospitals (including Emory University Hospital,
 Emory Midtown Hospital, Grady Memorial Hospital) and Emory University affiliated
 outpatient dialysis units

 -  Informed consent requirements: All study subjects must agree to participate in the
 study and provide written informed consent.

 Exclusion Criteria

 -  Age < 18 years

 -  Patients with a corrected serum calcium > 10.5 mg/dL within 4 weeks of study screening

 -  Current intake of > 2000 IU per day of Vitamin D3

 -  Subjects unable to provide informed consent or who plan to relocate outside of Atlanta
 during the study duration