A critical review of studies on vitamin D in relation to colorectal cancer

Nutr Cancer. 2004;48(2):115-23. doi: 10.1207/s15327914nc4802_1.


Vitamin D intake has been hypothesized to reduce the risk of several types of cancer. Vitamin D and its analogues have demonstrated anticancer activity in vitro and in animal models. However, the risk of colorectal cancer in relation to dietary vitamin D remains controversial. A literature search was performed for articles on epidemiologic studies of vitamin D and colorectal cancer and the mechanisms involved. Studies that combine multiple sources of vitamin D or examine serum 25(OH)D3 usually find that above-average vitamin D intake and serum metabolite concentrations are associated with significantly reduced incidence of colorectal cancer. A number of mechanisms have been identified through which vitamin D may reduce the risk of colorectal and several other types of cancer. Although studies that include vitamin D from all sources or serum 25(OH)D3 usually show significantly reduced incidence of colorectal cancer in association with vitamin D, analyses limited to dietary vitamin D tend to have mixed results. The likely reason that dietary vitamin D is not a significant risk reduction factor for colorectal cancer in many studies is that dietary sources provide only a portion of total vitamin D, with supplements and synthesis of vitamin D in the skin in association with solar UV-B radiation providing the balance. There is strong evidence from several different lines of investigation supporting the hypothesis that vitamin D may reduce the risk of colorectal cancer. Further study is required to elucidate the mechanisms and develop guidelines for optimal vitamin D sources and serum levels of vitamin D metabolites.

Publication types

  • Meta-Analysis
  • Review

MeSH terms

  • Anticarcinogenic Agents / administration & dosage*
  • Calcium, Dietary / administration & dosage
  • Case-Control Studies
  • Cohort Studies
  • Colorectal Neoplasms / epidemiology
  • Colorectal Neoplasms / prevention & control*
  • Dietary Supplements
  • Humans
  • Incidence
  • Risk Factors
  • Ultraviolet Rays
  • Vitamin D / administration & dosage*
  • Vitamin D / blood


  • Anticarcinogenic Agents
  • Calcium, Dietary
  • Vitamin D