Efficacy of Vitamin D in Colorectal Cancer Chemoprevention

Vitamin D's ability to prevent colorectal cancer (CRC) has been suspected for nearly 30 years, but has never been directly studied in humans. The biologically active version of vitamin D, 1,25(OH)2D3, cannot be readily used in humans because of its tendency to cause serum calcium levels to rise. In contrast, 25(OH)D3 (ie calcifediol) does not have this side effect. The investigators previous research suggests that the enzyme necessary to convert 25(OH)D3 (calcifediol) into active 1,25(OH)D3 is present in cells lining the large intestine (colon). Aberrant crypt foci (ACF) are very small (ie microscopic) collections of abnormally shaped cells that are a commonly used marker of CRC risk. Screening colonoscopy at UIC routinely uses methods that allow ACF counting to be done as a part of standard practice. ACF's are not fixed, like polyps or cancers, but can disappear as a person's risk for developing CRC decreases. The investigators propose giving patient's with 10 or more ACF's 25(OH)D3 (calcifediol) or placebo, and determining if there is a drug-dependant decrease in ACF number. The primary objective is to determine whether 25(OH)D3 (calcifediol) supplementation, compared to placebo, causes significant reduction of ACF number from baseline levels. The primary endpoint will be change in ACF number.

Sex

All

Minimum age

50 Years

Inclusion Criteria:

* All non-pregnant patients 50 years of age or older with 10 or more ACFs.

Exclusion Criteria:

* The following will be specifically looked for, and result in patients not being eligible for study enrollment:
* Use of non-steroidal anti-inflammatory drugs or glucocorticosteroids within 60 days of study entry.
* History of chronic IBD or prior pelvic radiation (inflammation distorts crypt pattern).
* Intake of any vitamin D or calcium supplements within 60 days of study entry.
* Patients with increased bleeding risk from biopsy protocol (i.e. renal failure, decompensated cirrhosis, blood dyscrasia