ONS Connect - September 2008 - (Page 23)

aClOSErlOOK Vitamin D and Cancer: More Questions Than Answers Remain [By robin M. Lally, PhD, RN, BA, AOCN ®, CNS, Contributing Editor] he fortification of milk with vitamin D in the 1930s virtually eliminated rickets in the U.S. population. Recent research, however, suggests that vitamin D also may play a role in cancer incidence and mortality. Vitamin D is essential for promoting calcium absorption, maintaining serum phosphate and calcium concentrations, promoting normal bone mineralization and growth, and modulating neuromuscular, immune, and cellular functions. Deficiencies in vitamin D (< 30 ng/ml serum 25-hydroxyvitamin D [25(OH) D]) among adults are common, owing to limited sun exposure in northern latitudes, consuming few fortified foods, or forgoing supplementation (200 – 400 IU daily). Although some evidence suggests that vitamin D plays a role in cancer prevention, attempting to demonstrate a consistent relationship between it and cancer in humans has proven to be difficult. For example, a prospective study of 16,818 participants in the Third Na- T tional Health and Nutrition Examination Survey found an inverse relationship between serum 25(OH)D levels at baseline and colorectal cancer deaths but no relationship with breast, prostate, or other cancer mortality (Freedman, Looker, Chang, & Graubard, 2007). Another study of 749 patients with prostate cancer and 781 matched controls also found no association between high levels of 25(OH)D and a reduced risk of developing prostate cancer (National Cancer Institute, 2008). On the other hand, a case control study of 1,394 women with breast cancer and 1,365 controls found that serum 25(OH) D levels did have a significant inverse relationship to postmenopausal breast cancer risk (Abbas et al., 2008). Intervention studies also have provided inconsistent results. The Women’s Health Initiative found no reduction in the incidence of colorectal cancer among 36,282 postmenopausal women, half of whom took either 400 IU of vitamin D with 1,000 mg calcium or placebo daily over seven years (WactawaskiWende et al., 2006). In contrast, a randomized, double-blind study of 1,179 postmenopausal women assigned to (a) 1,400–1,500 mg of calcium plus 1,100 IU vitamin D, (b) calcium alone, or (c) placebo found a 60% reduction in cancers among those taking vitamin D as compared to placebo over a four-year period (Lappe, Travers-Gustafson, Davies, Recker, & Heaney, 2007). However, the study’s sample size and ability to make statements about vitamin D’s effect on cancer incidence have been questioned (Beres, 2008). National Cancer Institute experts have determined that evidence linking vitamin D to cancer risk is inconsistent and merits further study to determine the dose that might be effective, optimal timing for its use, risks, and what cancers may be affected (Beres, 2008). ✱ Abbas, S., Linseisen, J., Slanger, T., Kropp, S., Mutschelknauss, E.J., Flesch-Janys, D., et al. (2008). Serum 25-hydroxyvitamin D and risk of post-menopausal breast cancer-results of a large case-control study. Carcinogenesis, 29(1), 93–99. Beres, S. (2008). Vitamin D: Cancer prevention’s sunny future? Journal of the National Cancer Institute, 100(5), 292–293, 297. Freedman, D.M., Looker, A.C., Chang, S.C., & Graubard, B.I. (2007). Prospective study of serum vitamin D and cancer mortality in the United States. Journal of the National Cancer Institute, 99(21), 1594–1602. Lappe, J.M., Travers-Gustafson, D., Davies, K.M., Recker, R.R., & Heaney, R.P. (2007). Vitamin D and calcium supplementation reduces cancer risk: Results of a randomized trial. American Journal of Clinical Nutrition, 85(6), 1586–1591. National Cancer Institute. (2008). Vitamin D not associated with decreased prostate cancer risk [Bulletin]. Retrieved August 21, 2008, from http://www.cancer.gov/ncicancerbulletin/NCI_ Cancer_Bulletin_052708/page3 Wactawaski-Wende, J., Kotche, J.M., Anderson, G.L., Assaf, A.R., Brunner, R.L., O’Sullivan, M.J., et al. (2006). Calcium plus vitamin D supplementation and the risk of colorectal cancer. New England Journal of Medicine, 354(7), 684–696. Contributing Editor Robin M. Lally, PhD, RN, BA, AOCN®, CNS, is a research assistant professor in the School of Nursing at the State University of New York at Buffalo. September 2008 ONS CONNECT 23 http://www.cancer.gov/ncicancerbulletin/NCI_Cancer_Bulletin_052708/page3 http://www.cancer.gov/ncicancerbulletin/NCI_Cancer_Bulletin_052708/page3

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ONS Connect - September 2008 Contents Editor's Note Just In Advances in Prostate Cancer Treatment A Year in the Life - Month Nine Web Connect Capitol Connection Manage Infusion Reactions From Cetuximab Notice Nursing Now Caregiver Care Oropharyngeal Cancer in Men Associated with HPV Working for You Calendar of Events Staying on Top

ONS Connect - September 2008

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