Breast cancerHow does vitamin D work?

The most important mechanisms whereby vitamin D reduces the risk of cancer in general result from its role as a nuclear transcription factor that regulates cell growth, differentiation, apoptosis and a wide range of cellular mechanisms central to the development of cancer including angiogenesis and metastasis1. Increased absorption of calcium also plays a role2.

A recent hypothesis has been proposed to explain the roles of vitamin D in reducing the risk of cancer incidence and death. Its seven phases are Disjunction, Initiation, Natural selection, Overgrowth, Metastasis, Involution, and Transition (abbreviated DINOMIT). Vitamin D metabolites prevent disjunction of cells and are beneficial in other phases3

A recent paper summarized the mechanisms whereby vitamin D reduces the risk of breast cancer in particular including inhibition of invasion, metastasis and tumor angiogenesis, suppression of COX-2 expression, thereby reducing levels and biological activity of proinflammatory prostaglandins. Vitamin D also decreases expression of aromatase, an enzyme involved in estrogen synthesis, and down-regulates estrogen effectiveness in promoting breast cancer proliferation4.

Page last edited: 22 August 2011


  1. Ingraham, B. A. Bragdon, B. Nohe, A. Molecular basis of the potential of vitamin D to prevent cancer. Curr Med Res Opin. 2008 Jan; 24 (1): 139-49.
  2. Peterlik, M. Grant, W. B. Cross, H. S. Calcium, vitamin D and cancer. Anticancer Res. 2009 Sep; 29 (9): 3687-98.
  3. Garland, C. F. Gorham, E. D. Mohr, S. B. Garland, F. C. Vitamin D for cancer prevention: global perspective. Ann Epidemiol. 2009 Jul; 19 (7): 468-83.
  4. Krishnan, A. V. Swami, S. Feldman, D. Vitamin D and breast cancer: inhibition of estrogen synthesis and signaling. J Steroid Biochem Mol Biol. 2010 Jul; 121 (1-2): 343-8.