Vitamin D has traditionally been considered to be solely related to bone health. The scientific community has only recently begun to recognize the remarkable role of vitamin D in disease prevention and management. Nowadays vitamin D is considered to be a hormone rather than a vitamin and it has been shown to play a central role in the healthy functioning of our bodies and particularly in cancer prevention.
As seen in the graph above, various studies have shown that as the levels of vitamin D in the blood increase, the incidence of major health problems is reduced. More specifically, heart attacks, Type I diabetes and hypertension decrease. Low vitamin D levels also result in a malfunctioning immune system and an increase in cancer risk.
According to Michael F. Holick, PhD, MD, who heads the Vitamin D, Skin, and Bone Research Laboratory at Boston University School of Medicine, activated vitamin D is one of the strongest inhibitors of cancer cell growth.
Vitamin D is required for normal cell growth
Vitamin D is one of the most potent hormones for regulating normal cell growth. It was recently discovered that many cell types contain vitamin D receptors. When these receptors are activated by vitamin D the cells grow, function and multiply in a healthy way. Vitamin D inhibits abnormal cells’ development and blocks the invasiveness, uncontrolled angiogenesis and metastatic potential of cancer cells.
Vitamin D protects healthy cells from becoming cancerous
According to many researchers on Vitamin D, such as David Feldman, M.D., Professor of Medicine at Stanford University School of Medicine, data from a large number of studies strongly suggest that vitamin D deficiency increases the risk of cancer development. Avoiding deficiency is critical in reducing cancer incidence and improving the outcome of any cancer treatment.
Cancers of the gastrointestinal tract
The protective relationship between sufficient vitamin D status and lower risk of cancer has been found in many studies. A study by Frank and Cedric Garland back in 1989 found that low levels of vitamin D in the blood (below 20 ng/mL), were associated with a doubling of the risk of developing colon cancer. A similar study for colorectal cancer found that a blood level of vitamin D of 34 ng/mL could reduce the incidence by half, whereas a level of 46 ng/mL could further reduce it by two thirds.
Vitamin D and breast cancer
Women with breast cancer are more likely to have low levels of vitamin D in their body. Some research has shown that post-menopausal women who don’t get very much vitamin D may be more likely to develop breast cancer later in life. It was also found that women who have breast cancer are more likely to develop bigger tumors and are more likely to have recurrent breast cancer if they have low levels of vitamin D.
In a review of many studies, researchers found that women with breast cancer who had low vitamin D levels had a more than double risk of their cancer coming back, and an almost double risk of dying compared to women with high vitamin D levels.
A study done in 2009 in Canada looked at a group of women who had an early stage of breast cancer and followed them over 12 years. They found that in women who have breast cancer, low levels of vitamin D are linked to worse outcomes like bigger tumors and cancer spreading to other parts of the body.
Vitamin D reduces the risk of metastasis
A large number of studies have concluded that adequate vitamin D levels are associated with a reduced risk of metastasis in cancer patients. Other studies showed that cancer patients with higher vitamin D levels lived significantly longer compared to patients with lower vitamin D levels. Vitamin D3 treatment significantly suppresses the viability of some cancers, as for example gastric cancer and vitamin D also acts synergistically with other anti-cancer drugs.
Optimize your Vitamin D levels
Vitamin D can be synthesized by the body when we expose our skin to the sun, and to a lesser degree it can be provided by our diet. Ultraviolet rays from the sun, the UVB rays, trigger the production of vitamin D in the outer layer of the skin.
Blood vitamin D level is among the most important factors related to the risk of developing cancer and a wide variety of other diseases. Vitamin D in the blood is measured in ng/ml or in nmol/l. To convert ng/ml to nmol/l multiply by 2.5 and to convert nmol/l to ng/ml multiply by 0.4.
It is vital to measure your vitamin D levels twice a year. If your vitamin D levels are below optimal you can take vitamin D supplements to keep your leves within the optimal range. Recent research showed that for maximum health, vitamin D levels need to be between 50 – 70 ng/ml year-round.
- Gorham ED, Garland CF, Garland FC, Grant WB, Mohr SB, Lipkin M, Newmark HL, Giovannucci E, Wei M, Holick MF. Vitamin D and prevention of colorectal cancer. J Steroid Biochem Mol Biol 2005; 97(1-2):179-194.
- Expert Review of Anticancer Therapy; Current progress in using vitamin D and its analogs for cancer prevention and treatment; June 2012, Vol. 12, No. 6 , Pages 811-837, Florence SG Cheung, Frank J Lovicu, and Juergen KV Reichardt
- Annual Review of Pharmacology and Toxicology; Mechanisms of the Anti-Cancer and Anti-Inflammatory Actions of Vitamin D; February 2012, Vol. 51: 311-336, Aruna V. Krishnan and David Feldman
- Jacqueline Moreno, Aruna V.Krishnan, Donna M.Peehl and David Feldman, Mechanisms of Vitamin D-mediated Growth Inhibition in Prostate Cancer Cells : inhibition of the Prostaglandin Pathway: Anticancer Research 26: 2525-2530 (2006)
- Garland CF, Garland FC, Shaw EK, Comstock GW, Helsing KJ, GorhamED.Serum25-hydroxyvitaminDandcoloncancer:eight-year prospective study. Lancet 1989;18:1176–78.
- Rose AAN, Elser C, Ennis M, et al. Blood levels of vitamin D and early stage breast cancer prognosis: a systematic review and meta-analysis. Breast Cancer Res Treat 2013;141:331-339.
- Goodwin PJ, Ennis M, Pritchard KI, et al. Prognostic effects of 25-hydroxyvitamin D levels in early breast cancer. J Clin Oncol 2009;27:3757-3763.
- Cedric F. Garland, Edward D. Gohgam et al, Vitamin D for Cancer Prevention: Global Perspective: Ann Epidemiol 2009;19:468–483