Studies suggest that Vitamin D may play an important role in the prevention and potentially even treatment of many forms of cancer. A recent four-year, randomized study at Creighton University following 1,179 healthy, postmenopausal women from rural eastern Nebraska, found that daily supplementation with only 1,100 iu of Vitamin D led to up to 77% fewer cases of all forms of Cancer:
Here's an easy to read summary article:
And the full study:
Studies also suggest that Vitamin D levels may be an important predictor of cancer survival and even cancer relapse rates:
Here's an easy to read summary article:And the cited summary articles:
- Serum 25-Hydroxyvitamin D3 Levels Are Associated With Breslow Thickness at Presentation and Survival From Melanoma
- Prospective study of predictors of vitamin D status and survival in patients with colorectal cancer.
The slide found @ minute 26 in the following presentation by Dr David Feldman, MD at Stanford provides an excellent overview of some of the currently suspected mechanisms of anti-cancer activities of Vitamin D3. They are:
- Inhibits G1/G0 cell cycle arrest
- Stimulates apoptosis
- Stimulates differentiation
- Regulates tumor suppressors / oncogenes
- Regulates growth factors or receptors
- Is anti-angiogenic
- Inhibits invasion and metastasis
- Is anti-inflammatory
BTW, this is a great video on the importance of Vitamin D3, and it includes a very good discussion on the Vitamin D pathways in general. Towards the end (@ the 20 minute mark), it discusses Vit D3 in relation to cancer, including a nice up-to-date list of the suspected mechanisms involved as copied above.
Below are a few supporting studies for each of the mechanisms of anti-cancer activity of Vit D3 discussed in the video above:
Inhibits G1/G0 cell cycle arrest:
- Novel 19-nor-hexafluoride vitamin D3 analog (Ro 25-6760) inhibits human colon cancer in vitro via apoptosis
- Synchronization of normal human keratinocyte in culture: its application to the analysis of 1,25-dihydroxyvitamin D3 effects on cell cycle
Stimulates Apoptosis:
Stimulates differentiation:
- Membrane initiated signaling by 1,25alpha-dihydroxyvitamin D3 in LNCaP prostate cancer cells
- Vitamin D, Pit-1, GH, and PRL: possible roles in breast cancer development
- Expression of human kinase suppressor of Ras 2 (hKSR-2) gene in HL60 leukemia cells is directly upregulated by 1,25-dihydroxyvitamin D(3) and is required for optimal cell differentiation
Regulates tumor suppressors / oncogenes:
- Vitamin D Arrests Thyroid Carcinoma Cell Growth and Induces p27 Dephosphorylation and Accumulation through PTEN/Akt-Dependent and -Independent Pathways
- Induction of kinase suppressor of RAS-1(KSR-1) gene by 1, alpha25-dihydroxyvitamin D3 in human leukemia HL60 cells through a vitamin D response element in the 5'-flanking region
Regulates growth factors or receptors:
- Role of vitamin D receptor in the antiproliferative effects of calcitriol in tumor-derived endothelial cells and tumor angiogenesis in vivo
- 1alpha,25-dihydroxyvitamin D3 (Calcitriol) inhibits hypoxia-inducible factor-1/vascular endothelial growth factor pathway in human cancer cells
Is anti-angiogenic:
- Role of vitamin D receptor in the antiproliferative effects of calcitriol in tumor-derived endothelial cells and tumor angiogenesis in vivo
- 1alpha, 25-dihydroxyvitamin D3 suppresses interleukin-8-mediated prostate cancer cell angiogenesis
- Inhibition of angiogenesis by vitamin D-binding protein: characterization of anti-endothelial activity of DBP-maf
Inhibits invasion and metastasis:
- 1alpha,25-dihydroxyvitamin D3 inhibits prostate cancer cell invasion via modulation of selective proteases
- 1 alpha,25-Dihydroxyvitamin D(3) is a preventive factor in the metastasis of lung cancer
- The vitamin D analogue EB 1089 prevents skeletal metastasis and prolongs survival time in nude mice transplanted with human breast cancer cells
Is anti-inflammatory:
- Calcitriol as a chemopreventive and therapeutic agent in prostate cancer: role of anti-inflammatory activity
- Selective inhibition of cyclooxygenase-2 (COX-2) by 1alpha,25-dihydroxy-16-ene-23-yne-vitamin D3, a less calcemic vitamin D analog
- 1alpha,25-Dihydroxyvitamin D3 modulates the response of human keratinocytes to ionizing radiation exposure
Vitamin D3 has also been shown to have anti-cancer effects through other mechanisms:
- Cancerous cells have been shown to require telomerase in order to survive (and avoid apoptosis) as the following article discusses:
"In 90 percent of cancers, no matter what caused the cancer to form, it needs telomerase activity to maintain the cell. Without telomerase, the cell will die." And Vitamin D3 has been shown to downregulate telomerase in several forms of cancer:
- Induction of ovarian cancer cell apoptosis by 1,25-dihydroxyvitamin D3 through the down-regulation of telomerase
- Combination treatment with 1alpha,25-dihydroxyvitamin D3 and 9-cis-retinoic acid directly inhibits human telomerase reverse transcriptase transcription in prostate cancer cells
Here's another great video on Vitamin D3 and cancer. Pay particular attention to the discussion on the potential involvement of Tight Junctions and Adherins in cancer development and progression starting @ minute 20:00:
Additional studies suggesting the role Vitamin D3 plays in cancer can be found on the Vitamin D Council page on Vitamin D and Cancer: