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Defining Optimal Doses of Vitamin D for Chemoprevention in Blacks.

Phase 1
30 Years
80 Years
Open (Enrolling)
Gastrointestinal Cancers, Prostate Cancer, Hypertension

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Trial Information

Defining Optimal Doses of Vitamin D for Chemoprevention in Blacks.

- Participants will be asked to answer some questions about their diet, exercise and
health. In addition, participants blood pressure will be taken. These assessments
will occur at baseline, 3- and 6-month appointments. At baseline only, we will measure
skin tone with a tool called the Photovolt 577.

- A small blood sample will be taken to see how much Vitamin D is the body and will also
look at levels of other markers of disease such as proteins, hormones, and genes.

- Participants will take a vitamin pill every day for three months and be randomly
assigned to one of four different types of pills.

- Participants will be called or visited at least every two weeks. They will be asked
questions to determine if they have any side effects associated with high levels of
Vitamin D.

- At the beginning of the second and third months, participants will be provided with
more pills. At the end of the third month, another blood sample will be taken. Three
months after that, the final blood sample will be taken.

Inclusion Criteria:

- Between the ages of 30 and 80 years

- Comfortable communicating in English

- Currently has a primary care physician

- Willing to discontinue vitamin D or calcium supplements

- Willing to have all protocol specific tests run

Exclusion Criteria:

- Plans on taking a vacation or travel to a sunny region within 3 months of vitamin
supplementation period except for a short period (i.e. 1 weekend)

- Pregnant or breast feeding or planning on becoming pregnant in the following year

- Pre-existing calcium (including hypercalcemia), parathyroid conditions (including
hyperparathyroidism), sarcoidosis

- No concurrent active malignancies (other than non-melanoma skin cancer) or previous
diagnosis of prostate cancer

- Cognitively impaired

- Active thyroid disease (e.g. Graves, Hashimoto's or thyroiditis)

- History of nephrolithiasis, chronic liver disease, chronic renal disease, or renal

Type of Study:


Study Design:

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Prevention

Outcome Measure:

Among Blacks, identify a dose of oral vitamin D supplementation that will result in levels of plasma 25(OH)D that would be predicted to reduce colorectal cancer incidence.

Outcome Time Frame:

Baseline, 3months, 6months

Safety Issue:


Principal Investigator

Edward Giovannucci, MD, ScD

Investigator Role:

Principal Investigator

Investigator Affiliation:

Harvard School of Public Health/Brigham and Women's Hospital


United States: Institutional Review Board

Study ID:




Start Date:

October 2007

Completion Date:

December 2013

Related Keywords:

  • Gastrointestinal Cancers
  • Prostate Cancer
  • Hypertension
  • Vitamin D
  • Blacks
  • cancer
  • hypertension
  • Hypertension
  • Prostatic Neoplasms
  • Gastrointestinal Neoplasms



Dana-Farber Cancer Institute Boston, Massachusetts  02115