In a previous post from January 27, 2016 (http://blog1.smopinions.com/2016/01/7-interesting-facts-about-vitamin-d.html), it was mentioned that there are associations between vitamin D deficiency and certain types of cancer. This post will explain a little bit more about them.
Regarding colorectal cancer, it was noticed about 2 decades ago, that there is more mortality from colorectal cancer in the northern and northeastern parts of the United States, the ones which receive less sunlight. This in itself is not enough to establish a meaningful association, however, it gave a starting point for research. Then, 2 studies showed that having levels above 30 ng/dL in the blood may reduce the incidence of colorectal cancer by half1,2.
With respect to breast cancer, a recent study found that postmenopausal women may get a benefit from having adequate vitamin D levels in the blood. The risk of developing breast cancer in this particular group of women was lower than in the same group of women with lower vitamin D in their blood3.
Finally, in regards to prostate cancer, it has been found that this cancer is also more common in regions with less sun exposure. In addition, lower vitamin D levels in the blood are related to more aggressive forms of prostate cancer. Last but not least, adequate levels of vitamin D may aid in the slowing of the progression of this type of cancer4.
More research is needed in order to confirm and strengthen these associations. In the mean time, it does not hurt to have adequate levels of vitamin D in the blood, particularly for people living north of the 30th parallel.
1. Serum 25-hydroxyvitamin D and colon cancer: eight-year prospective study. Garland CF, Comstock GW, Garland FC, Helsing KJ, Shaw EK, Gorham ED. Lancet. 1989;2(8673):1176-8.
2. Meta-analysis: longitudinal studies of serum vitamin D and colorectal cancer risk. Yin L, Grandi N, Raum E, Haug U, Arndt V, Brenner H. Alim Pharm Therap. 2009 30(2):113-25
3. Plasma vitamin D levels, menopause, and risk of breast cancer: dose-response meta-analysis of prospective studies. Bauer SR, Hankinson SE, Bertone-Johnson ER, Ding EL. Medicine (Baltimore). 2013;92(3):123-31
4. Association between serum 25(OH)D and death from prostate cancer. Tretli S, Hernes E, Berg JP, Hestvik UE, Robsahm TE. Br. J. Cancer 2009;100(3):450-4.
Marco A. Ramos MD