Vitamin D Replacement After Kidney Transplant

Vitamin D deficiency accelerates vascular risk progression after kidney transplant.

Study Overview

• Status: Completed
• Conditions: Vitamin D Deficiency; Kidney Transplantation
• Intervention / Treatment: Dietary supplement: Standard vitamin D3 treatment; Dietary supplement: High dose vitamin D3 treatment

Detailed Description

This trial will assess the following aims:

1. Time to plateau vitamin D concentrations after initiating vitamin D supplements
2. Safety of vitamin D replacement based on serum and urine calcium
3. Effect of vitamin D on PTH concentration in individuals with elevated parathyroid hormone
4. Effect of vitamin D on markers of insulin resistance and inflammation

• Study Type: Interventional
• Enrollment (Actual): 116
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Nebraska
    • Omaha, Nebraska, United States, 68198
      • University of Nebraska Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 19 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Kidney transplant more than 6 months ago
• 19 years or older
• 25-hydroxy vitamin D ≤35 ng/ml

Exclusion Criteria:

• Estimated Glomerular filtration rate (GFR) <30 ml/min/1.73m²
• Previous small bowel or lung transplant
• Pancreas transplant less than 6 months ago
• Cancer or any condition that would change their weight dramatically in the near future such as malabsorption
• Willing to return for testing every two months
• Women who are pregnant or < 6 weeks postpartum
• Calcium > 10.5 mg/dl
• Phosphate > 4.8 mg/dl
• Drinking more than 2 alcohol drinks a day or 14 drinks per week
• History of parathyroid surgery
• Known granulomatous disease
• Taking any seizure medication that affects vitamin D
• Taking Zemplar ® and/or Rocaltrol ®
• History of kidney stones in the past 20 years
• Not on a stable dose of bisphosphonate for the past three months
• Planning on a pancreas transplant within the next year
• In any other research study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Standard vitamin treatment; 10,000 I.U. of vitamin D3 weekly	Dietary supplement: Standard vitamin D3 treatment; 10,000 I.U./wk of vitamin D3 orally for 6 months
Active Comparator: 50,000 I.U. of vitamin D3; 50,000 I.U. of vitamin D3 weekly	Dietary supplement: High dose vitamin D3 treatment; 50,000 I.U./wk of vitamin D3 orally for 6 months; Other Names: D3, vitamin D

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Compare Efficacy and Safety of Two Vitamin D Supplements of These Doses in Normalizing Vitamin D Concentrations.	The 6 month change (6 month - Baseline) was compared between the two treatment arms of vitamin D supplements for normalizing vitamin D concentrations. Higher change values indicate improvement in vitamin D levels.	Baseline and 6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The Ability of Vitamin D to Reduce Parathyroid Hormone Concentration.	The 6 month change (6 month - Baseline) in parathyroid hormone concentration was compared between the two treatment arms.	baseline and 6 months
The Ability of Vitamin D to Alter Spot Urine Protein-Creatinine Ratio.	The 6 month change (6 month - Baseline) in spot urine protein-creatinine ratio was compared between the two treatment arms.	6 months
The Effect of Vitamin D Supplementation on 6 Month High-sensitivity C-reactive Protein (HsCRP) Levels.	The 6 month change in High-sensitivity C-reactive protein (HsCRP) levels was compared between the two treatment arms.	Baseline and 6 months
The Effect of Vitamin D Supplementation on Insulin Resistance at 6 Months	The 6 month change (6 month - Baseline) in insulin resistance was assessed with HOMA-IR (Homeostatic Model Assessment-Insulin Resistance), which is calculated by fasting glucose (mg/dL) X fasting insulin (mU/L) /405.	Baseline and 6 months

Collaborators and Investigators

• Sponsor: University of Nebraska
• Investigators: Principal Investigator: Jennifer L Larsen, MD, University of Nebraska

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2008
• Primary Completion (Actual): April 1, 2012
• Study Completion (Actual): June 8, 2023

Study Registration Dates

• First Submitted: September 4, 2008
• First Submitted That Met QC Criteria: September 5, 2008
• First Posted (Estimated): September 8, 2008

Study Record Updates

• Last Update Posted (Actual): October 26, 2024
• Last Update Submitted That Met QC Criteria: August 5, 2024
• Last Verified: August 1, 2024

More Information

Terms related to this study

• Keywords: Vitamin D deficiency; Insulin resistance (IR); Cardiovascular Disease (CVD); Parathyroid hormone (PTH); Kidney transplantation (KTX); Vascular risk; Carotid intima media thickness (CIMT)
• Additional Relevant MeSH Terms: Nutrition Disorders; Avitaminosis; Deficiency Diseases; Malnutrition; Vitamin D Deficiency; Calcium-Regulating Hormones and Agents; Physiological Effects of Drugs; Bone Density Conservation Agents; Micronutrients; Vitamin D; Ergocalciferols; Vitamins; Cholecalciferol
• Other Study ID Numbers: 0382-08-FB

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No