News — The American Cancer Society just published a paper reporting that while breast cancer incidence rates for 2008-2012 were similar for black and white women, death rates were 42% higher for black women [DeSantis, 2015]. The factors suggested to explain the disparity in mortality rates included difference in stage at diagnosis, obesity, comorbidities, tumor characteristics, as well as access, adherence, and response to treatments.
However, a study in California found that body mass index did not affect survival rates for black American women [Kwan, 2014].
No mention of the role of vitamin D in reducing risk of breast cancer and increasing survival after diagnosis was made in the American Cancer Society paper.
Case-control studies consistently find a strong protective effect of higher 25-hydroxyvitamin D concentrations at time of breast cancer diagnosis [Grant, 2015]. Two clinical trials found that vitamin D plus calcium reduced the risk of cancer including breast cancer [Lappe, 2007], [Bolland, 2011].
Also, women who live in the sunny states have much lower breast cancer mortality rates than those who live in the cloudy states in the north [John, 2007]. Solar ultraviolet-B exposure is the primary source of vitamin D for most people.
A review of differences in cancer survival rates found that after consideration of stage at diagnosis, socioeconomic status, and treatment, black Americans had about 25% increased mortality rates for most types of cancer [Grant, 2012]. The difference was consistent with the fact that black Americans have 25-hydroxyvitamin D concentrations about 40% lower than white Americans since their dark skin reduces the production rate of vitamin D in the sun.
A paper from the Roswell Park Cancer Center concluded "The relationship of vitamin D with breast cancer risk may be subtype-specific, with emerging evidence of stronger effects of vitamin D for more aggressive breast cancer, particularly in women of African ancestry." [Yao, 2013].
Further evidence that vitamin D concentration affects cancer survival rates comes from a nine-year study in Norway. The hazard ratio for the nine-year all-cause survival after diagnosis of breast cancer was much lower (63% lower) for women with higher 25-hydroxyvitamin D concentrations [Tretli, 2012].
Based on results in the peer-reviewed scientific literature [Baggerly, 2015], cancer incidence and mortality rates could be greatly reduced if everyone had 25-hydroxyvitamin D concentrations above 40 ng/mL.An all-source vitamin D3 input of 4000 IU/d ensures that 50% of the population achieves 25-hyderoxyvitamin D concentrations above 40 ng/mL (8000 IU/d is needed for 90% of the population). [Garland, 2011]. The benefits of sunlight and vitamin D for public health were discussed at a seminar held by GrassRootsHealth.net in December 2014 [Baggerly, 2015].
References
Baggerly CA, Cuomo RE, French CB, Garland CF, Gorham ED, Grant WB, Heaney RP, Holick MF, Hollis BW, McDonnell SL, Pittaway M, Seaton P, Wagner CL, Wunch A. Sunlight and vitamin D: Necessary for public health. J Am Coll Nutr. 2015;34(4):359-65.
Bolland MJ, Grey A, Gamble GD, Reid IR. Calcium and vitamin D supplements and health outcomes: a reanalysis of the Women's Health Initiative (WHI) limited-access data set.Am J ClinNutr. 2011;94(4):1144-9.
DeSantis CE, Fedewa SA, Goding Sauer A, Kramer JL, Smith RA, Jemal A. Breast cancer statistics, 2015: Convergence of incidence rates between black and white women.CA Cancer J Clin.2015 Oct 29.doi: 10.3322/caac.21320. [Epub ahead of print]
Garland CF, French CB, Baggerly LL, Heaney RP. Vitamin D supplement doses and serum 25-hydroxyvitamin D in the range associated with cancer prevention. Anticancer Res. 2011;31(2):607-11.
Grant WB, Peiris AN. Differences in vitamin D status may account for unexplained disparities in cancer survival rates between African and White Americans. Dermatoendocrinol. 2012;4(2):85-94.
Grant WB. 25-Hydroxyvitamin D and breast cancer, colorectal cancer, and colorectal adenomas: case–control versus nested case–control studies, Anticancer Res. 2015;35(2):1153-60. www.ar.iiarjournals.org/cgi/pmidlookup?view=long&pmid=25667506
John EM, Schwartz GG, Koo J, Wang W, Ingles SA. Sun exposure, vitamin D receptor gene polymorphisms, and breast cancer risk in a multiethnic population. Am J Epidemiol. 2007;166(12):1409-19.
Kwan ML, John EM, Caan BJ, Lee VS, Bernstein L, Cheng I, Gomez SL, Henderson BE, Keegan TH, Kurian AW, Lu Y, Monroe KR, Roh JM, Shariff-Marco S, Sposto R, Vigen C, Wu AH. Obesity and mortality after breast cancer by race/ethnicity: The California Breast Cancer Survivorship Consortium. Am J Epidemiol. 2014;179(1):95-111.
Lappe JM, Travers-Gustafson D, Davies KM, Recker RR, Heaney RP. Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial. Am J ClinNutr. 2007;85(6):1586-91.
Tretli S, Schwartz GG, Torjesen PA, Robsahm TE. Serum levels of 25-hydroxyvitamin D and survival in Norwegian patients with cancer of breast, colon, lung, and lymphoma: a population-based study. Cancer Causes Control. 2012;23(2):363-70.
Yao S, Ambrosone CB. Associations between vitamin D deficiency and risk of aggressive breast cancer in African-American women. J Steroid Biochem Mol Biol. 2013;136:337-41.
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