Effect of Vitamin D and Calcium on Genes in the Colon

Adenocarcinoma Clinical Trial

Official title: High vs. Low Calcium Intake in the Presence of High Vitamin D: Effect on Gene Expression in the Colon

Status Completed

Clinical Trial Summary

The researchers are involved in a research program to understand how vitamin D and calcium in the diet or as supplements may lower the risk of colorectal polyps and cancer. To that end, the researchers are conducting a study of vitamin D supplementation in which volunteer subjects are provided a Western style diet for 2 separate 4 week periods at the Rockefeller University Hospital. During one of these 4 week inpatient periods, subjects receive calcium supplements and during the other 4 week inpatient period they receive a placebo tablet. The researchers determine changes within the colon as a result of supplementing the vitamin D in the presence of high and low calcium. A more detailed description of the study is provided below.

Clinical Trial Description

Study subjects participate for about 3 months. During this time, there is one outpatient visit, a 4 week inpatient period, a 4 week outpatient period known as a wash out period and finally another 4 week inpatient period. During the inpatient periods, the Rockefeller University Hospital (RUH) becomes your home. The subject must sleep here every night and consume all the food provided. During the screening visit, blood and urine samples will be taken and an EKG (electrocardiogram) and a complete physical exam will be done. After enrollment into the study, the first 4 week inpatient period begins. You may continue to go to work or do other activities as long as you eat the diet provided and sleep at the Rockefeller University Hospital. You must eat everything that we give you and you may not substitute or supplement the diet in any way. During each 4 week stay at the Rockefeller University Hospital, there will be three flexible sigmoidoscopies done and biopsies taken of the mucosal lining of the colorectum. This procedure is painless and takes about 5 minutes. In addition, blood samples will be taken every few days for follow-up and research, and two 24 hour urine samples will be done on separate days during the hospitalization. Vital signs are measured every day and your weight will be measured three times per week. During the four week wash out period, the subject will return to their home, go about their normal activities and consume their normal diet. The subject will return to the Rockefeller University Hospital for the second 4 week inpatient period. The procedures and laboratory tests are the same during the second inpatient period. The study concludes with the subjects' discharge from the RUH. ;

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Crossover Assignment, Masking: Double Blind (Subject, Caregiver, Investigator), Primary Purpose: Prevention

Related Conditions & MeSH terms

• Adenocarcinoma
• Colorectal Adenoma
• Colorectal Polyps

• NCT number: NCT00298545
• Study type: Interventional
• Source: Rockefeller University
• Status: Completed
• Phase: Phase 1
• Start date: November 2005
• Completion date: May 2009