Oral Vitamin C for Correction of Anemia in Patients Receiving Peritoneal Dialysis

Randomized, Double-Blind, Placebo-Controlled Trial of Oral Vitamin C on Correction of Anemia in Patients Receiving Peritoneal Dialysis

People with kidney failure are at risk for the development of anemia. Anemia is a decrease in the production of hemoglobin, a substance that carries oxygen in the blood. The majority of patients require erythropoietin and iron supplementation to correct the anemia. In some patients, the hemoglobin fails to rise to a desired level despite treatment with erythropoietin and iron. There have been several studies in hemodialysis patients showing that vitamin C given intravenously helps to correct anemia in patients already on erythropoietin and iron.

The purpose of this study is to determine whether oral vitamin C will improve parameters of anemia in patients receiving peritoneal dialysis.

Description of the research

This is a randomized, double blind, placebo controlled study. Participants will be randomized in a 1:1 ratio to oral vitamin C 500mg once a day or placebo for 3 months. All participants will be receiving oral iron supplementation, subcutaneous erythropoietin and a B and C complex vitamin containing 100mg of vitamin C. Lab parameters (hemoglobin, TSAT, ferritin) will be done at baseline and then monthly. The primary outcome is percent change from baseline in transferrin saturation. Secondary objectives are percent change in ferritin, hemoglobin and erythropoietin dose from baseline.

Study Overview

• Status: Completed
• Conditions: Anemia; Peritoneal Dialysis
• Intervention / Treatment: Dietary supplement: placebo; Dietary supplement: Vitamin C

Detailed Description

Patients will be randomized in a 1:1 ratio to Vitamin C 500mg orally once daily or matching placebo for 3 months. Randomization codes will be kept by the Research Pharmacy and investigators and patients will be blinded to treatment. Patients currently taking vitamin C supplements (excluding the 100mg of vitamin C contained in a B and C complex vitamin, a supplement used by all peritoneal dialysis patients), will be taken off the vitamin C and then randomized to one of the treatment arms after a 1 month washout period. At the end of 3 months, the effects of vitamin C on the change in transferrin saturation from baseline will be evaluated to identify which patients, if any, benefited from treatment. Hemoglobin, serum iron, total iron binding capacity, ferritin, transferrin saturation and erythropoietin dose will also be assessed. The dose and formulation of recombinant erythropoietin and oral iron will be adjusted during the study period according to standard practice algorithms currently used in the clinic. The addition of vitamin C does not pose any risk to the patients and will be dispensed to the patient by the Research Pharmacy at St. Michael's Hospital free of charge.

Patient population Inclusion criteria Receiving peritoneal dialysis for 2 months

Exclusion criteria Red blood cell folate < 3.9 nmol/L Serum B12 <110 pmol/L Bleeding, blood transfusions, acute liver disease in the previous 3 months

Assessments Parathyroid hormone Baseline B12 Baseline Folate Baseline Hemoglobin Baseline and monthly Hematocrit Baseline and monthly Ferritin Baseline and monthly Transferrin saturation Baseline and monthly Serum iron Baseline and monthly

• Study Type: Interventional
• Enrollment (Actual): 32
• Phase: Phase 3

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5B 1W8
      • St. Michael's Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Receiving peritoneal dialysis for 2 months

Exclusion Criteria:

Red blood cell folate < 3.9 nmol/L

• Serum B12 <110 pmol/L
• Bleeding, blood transfusions, acute liver disease in the previous 3 months

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: TRIPLE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
PLACEBO_COMPARATOR: placebo	Dietary supplement: placebo
ACTIVE_COMPARATOR: vitamin C; vitamin C 500mg orally once a day	Dietary supplement: Vitamin C; vitamin C 500mg orally once a day

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
difference in percent change from baseline to 3 months in transferrin saturation between vitamin C and placebo	3 months

Secondary Outcome Measures

Outcome Measure	Time Frame
difference in percent change from baseline to 3 months in hemoglobin,ferritin and epoetin dose (each determined separately)	3 months

Collaborators and Investigators

• Sponsor: Unity Health Toronto
• Investigators: Principal Investigator: Lori A MacCallum, PharmD, Unity Health Toronto

Study record dates

Study Major Dates

• Study Start: March 1, 2002

Study Registration Dates

• First Submitted: June 12, 2009
• First Submitted That Met QC Criteria: June 12, 2009
• First Posted (ESTIMATE): June 15, 2009

Study Record Updates

• Last Update Posted (ESTIMATE): June 15, 2009
• Last Update Submitted That Met QC Criteria: June 12, 2009
• Last Verified: June 1, 2009

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Hematologic Diseases; Anemia; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Protective Agents; Micronutrients; Vitamins; Antioxidants; Ascorbic Acid
• Other Study ID Numbers: 02-044