Vitamin D: powerful cancer protection
Vitamin D insufficiency is common among Americans overall but more prevalent among African Americans. A recent review of the literature suggests that vitamin D insufficiency is a key contributor to cancer survival disparities that exist between African Americans and white Americans (darker skin is less efficient at producing vitamin D in response to UV rays).1 A striking part of this literature review is the comprehensive summary of the existing data on vitamin D status and cancer survival: the authors present a long list of studies reporting that vitamin D adequacy is associated with reduced risk of death in all cancers combined, breast, colorectal, lung, and prostate cancer, leukemia and lymphomas.1
A protective effect of vitamin D against cancers was first proposed in 1980, based on an earlier observation that colon cancer mortality was the highest in geographical areas exposed to the least amounts of sunlight.2, 3 Several more studies of geographical variations in cancers have found the same result: inverse relationships exist between sun exposure and 24 types of cancer, including the most common cancers – those of the breast, colon, rectum, and prostate.4, 5
Since 1980, evidence for the involvement of vitamin D in the relationship between sun exposure and decreased cancer risk has progressively accumulated, as associations were found between blood vitamin D levels and reduced risk of cancers.6, 7 Further support for the importance of vitamin D in cancer prevention was provided by randomized controlled trials of vitamin D supplementation that showed reduced cancer risk compared to placebo. There have also been many reports that vitamin D receptor gene mutations, which interfere with the normal biological actions of vitamin D, were associated with increased cancer risk.8-10
Additional studies confirmed that vitamin D has growth-inhibitory effects on cells derived from breast, colon, prostate, and skin cancers.11 Vitamin D can block cancer cell growth in a number of ways: Vitamin D alters the expression of genes that regulate inflammation, cell death and cell proliferation, and also interferes with the growth-promoting actions of IGF-1 and other growth factors. Additional anti-cancer effects of vitamin D include enhanced DNA repair and immune defenses, and angiogenesis inhibition.12
Today, over 800 scientific papers have been published on the relationship between vitamin D and cancers. We now have ample evidence that maintaining adequate vitamin D levels is an effective strategy for protection against cancer.
Considering all of this evidence, achieving vitamin D sufficiency is so very important. Unfortunately, the Institute of Medicine is hesitant to significantly raise its vitamin D recommendations, so most multivitamins still do not contain nearly enough vitamin D (only 400 IU) to offer the security that a normal Vitamin D level will be achieved. This is an important reason why I designed my new Men’s and Women’s Daily Formula + D multivitamins to include 2000 IU of vitamin D3. In my experience, 2000 IU has been an appropriate dose to bring most people into the favorable blood 25(OH)D range of 30-50 ng/ml (I also recommend getting a blood test to confirm adequate levels). These are the only multivitamin supplements with a 2000 IU dose of D3 plus no folic acid, beta-carotene, copper, and vitamin A. This enables most people to get everything they need without needing to take multiple different products. For extra assurance, I’ve also utilized Vitamin D3 because of its highest biological value thus offering the most protection, which also is most effective for raising 25(OH)D levels.13 My goal is to make it as easy as possible to maintain healthy vitamin D levels, with plenty of D3 in a multivitamin which also gives you everything else that is worthy of supplementing, and carefully avoiding those supplemental ingredients that are potentially harmful; so additional supplements aren’t necessary to obtain the anti-cancer and bone-protective benefits of vitamin D and the other recommended nutrients.
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1. Grant WB, Peris AN. Differences in vitamin D status may account for unexplained disparities in cancer survival rates between African and White Americans. DermatoEndocrinology 2012;4.
2. Garland CF, Garland FC. Do sunlight and vitamin D reduce the likelihood of colon cancer? Int J Epidemiol 1980;9:227-231.
3. Apperly FL. The Relation of Solar Radiation to Cancer Mortality in North America. Cancer Res 1941;1:191-195.
4. Grant WB, Garland CF. The association of solar ultraviolet B (UVB) with reducing risk of cancer: multifactorial ecologic analysis of geographic variation in age-adjusted cancer mortality rates. Anticancer Res 2006;26:2687-2699.
5. Grant WB. Ecological studies of the UVB-vitamin D-cancer hypothesis. Anticancer Res 2012;32:223-236.
6. Gandini S, Boniol M, Haukka J, et al. Meta-analysis of observational studies of serum 25-hydroxyvitamin D levels and colorectal, breast and prostate cancer and colorectal adenoma. Int J Cancer 2011;128:1414-1424.
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10. Bolland MJ, Grey A, Gamble GD, et al. Calcium and vitamin D supplements and health outcomes: a reanalysis of the Women's Health Initiative (WHI) limited-access data set. Am J Clin Nutr 2011;94:1144-1149.
11. Fleet JC. Molecular actions of vitamin D contributing to cancer prevention. Mol Aspects Med 2008;29:388-396.
12. Fleet JC, DeSmet M, Johnson R, et al. Vitamin D and cancer: a review of molecular mechanisms. Biochem J 2012;441:61-76.
13. Tripkovic L, Lambert H, Hart K, et al. Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysis. Am J Clin Nutr 2012.