Vitamin D/Calcium Polyp Prevention Study

Completed · Phase 2/Phase 3 · Has a placebo group

Conditions studied: Colorectal Cancer, Polyps, Adenomas

In brief

Extensive experimental and observational data suggest that intake of calcium and of vitamin D exert protective effects on colorectal neoplasia. Building on their previous work, the investigators will investigate the chemopreventive effect of vitamin D in the large bowel, to study whether calcium with vitamin D is more effective than calcium alone, and to confirm their positive finding regarding calcium. The goal of this study is the development of chemopreventive combinations that will reduce risk of colorectal neoplasia sufficiently to permit the lengthening of surveillance intervals in most patients and to clarify important issues regarding the mechanisms of colorectal carcinogenesis and chemoprevention.

Key facts

Study ID

NCT00153816

Run by

Dartmouth-Hitchcock Medical Center

People needed

2813

Starts

2004-07-01

Expected to finish

2016-06-01

Last updated by the study team

2017-03-15

Who can join

Age: 45 and older, up to 75. Sex: any. Healthy volunteers: not accepted.

You may qualify if…

• One or more histologically verified neoplastic polyp (adenoma) that is at least 2 mm in size removed from the large bowel with the entire large bowel examined by colonoscopy and documented to be free of further polyps or areas suspicious for neoplasia within 120 days of study entry
• Anticipated colonoscopic follow-up three years or five years after the qualifying colonoscopy
• Age between 45 and 75 years at enrollment
• (Women)Agreement to avoid pregnancy (i.e., use of standard contraception)
• Willingness to forego calcium supplementation (including multivitamins containing calcium) or, for women only, option of taking calcium supplementation of 1200 mg/daily (contained in the study pills)
• Willingness to forego vitamin D supplementation (including multivitamins containing vitamin D)
• Agreement to daily dietary intake of the equivalent of not more than 1200 mg calcium
• Agreement to daily dietary intake of the equivalent of not more than 400 IU vitamin D
• Blood calcium level within normal range
• Blood creatinine level not to exceed 20% above upper limit of normal
• Serum 25-(OH)-vitamin D within lower limit of normal to 70 ng/ml
• Ability and willingness to follow the study protocol, as indicated by provision of informed consent to participate
• Good general health, with no severely debilitating diseases or active malignancy that might compromise the patient's ability to complete the study

You may not qualify if…

• General exclusionary criteria:
• Participation in another colorectal (bowel) study (intervention study) in the past 5 years
• Current participation in any other clinical trial (intervention study)
• Pregnancy or lactation
• A diagnosis of narcotic or alcohol dependence in the past 5 years
• A diagnosis of dementia (e.g. Alzheimer's) in the past 5 years
• A diagnosis of a significant psychiatric disability (e.g. Schizophrenia, refractory bipolar disorder, current severe depression) in the past 5 years
• Exclusions due to derangement of calcium metabolism or indications /contraindications to study agents:
• Any diagnosis of kidney stones
• A diagnosis of granulomatous diseases, e.g. sarcoidosis, active chronic fungal or mycobacterial infections (tuberculosis, histoplasmosis, coccidioidomycosis, blastomycosis), berylliosis, Wegener's granulomatosis in the past 5 years
• A diagnosis of hyperparathyroidism or other serious disturbance of calcium metabolism in the past 5 years
• A diagnosis of severe kidney disease, e.g. chronic renal failure in the past 5 years
• A diagnosis of unexplained hypercalcemia in the past 5 years
• Any Diagnosis of osteoporosis with physician recommendation for treatment of low bone mass
• A diagnosis of two or more low trauma fractures in the past 5 years
• A diagnosis of a medical condition requiring treatment with vitamin D (e.g. osteomalacia) in the past 5 years
• Exclusions due to intestinal or bowel problems:
• Any diagnosis of invasive carcinoma of the large bowel (even if confined to a polyp)
• Any diagnosis of familial colorectal cancer syndromes, e.g. Familial Adenomatous Polyposis (FAP) (including Gardner syndrome, Turcot's syndrome), Hereditary Nonpolyposis Colorectal Cancer (HNPCC), Hamartomatous Polyposis syndromes (including Peutz-Jeghers or Familial Juvenile Polyposis)
• Any diagnosis of inflammatory bowel disease, e.g. Crohn's Disease, Ulcerative Colitis
• A diagnosis of chronic intestinal malabsorption syndromes, e.g. celiac sprue, bacterial overgrowth, chronic pancreatitis, pancreatic insufficiency in the past 5 years
• Any large bowel resection
• Exclusions due to poor health:
• A diagnosis of malignancy, other than non-melanoma skin cancer in the past 5 years
• A diagnosis of severe lung disease - class 3 or 4 (e.g. chronic obstructive pulmonary disease or emphysema requiring oxygen) in the past 5 years

Where it is running

• University of Southern California — Los Angeles, California, United States
• University of Colorado — Denver, Colorado, United States
• Emory University — Atlanta, Georgia, United States
• University of Iowa — Iowa City, Iowa, United States
• University of Minnesota — Minneapolis, Minnesota, United States
• Dartmouth Hitchcock Medical Center — Lebanon, New Hampshire, United States
• University of North Carolina — Chapel Hill, North Carolina, United States
• Cleveland Clinic Foundation — Cleveland, Ohio, United States
• University of South Carolina — Columbia, South Carolina, United States
• University of Texas — Houston, Texas, United States
• University of Puerto Rico — San Juan, Puerto Rico

Full record on ClinicalTrials.gov

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