Robien K, Cutler GJ, Lazovich DVitamin D intake and breast cancer risk in postmenopausal women: the Iowa Women's Health Study. Cancer Causes Control 18(7): 775-782

Division of Epidemiology and Community Health, University of Minnesota School of Public Health, 1300 S. Second St., Suite 300, Minneapolis, MN 55454, USA.
Cancer Causes and Control (Impact Factor: 2.74). 09/2007; 18(7):775-82. DOI: 10.1007/s10552-007-9020-x
Source: PubMed


Vitamin D, a prosteroid hormone with anti-proliferative and pro-differentiation activity, is thought to act as a cancer chemopreventive agent. This study evaluated the association between vitamin D intake and breast cancer risk among women in a large prospective cohort study. A total of 34,321 postmenopausal women who had completed a questionnaire that included diet and supplement use were followed for breast cancer incidence from 1986 to 2004. Adjusted relative risks (RR) for breast cancer were calculated for dietary, supplemental, and total vitamin D intake among all women. The adjusted RR of breast cancer for women consuming >800 IU/day versus <400 IU/day total vitamin D was 0.89 (95% CI: 0.77-1.03). RRs were stronger among women with negative than positive ER or PR status. The association of high vitamin D intake with breast cancer was strongest in the first 5 years after baseline dietary assessment (RR = 0.66; 95% CI: 0.46-0.94 compared with lowest-intake group), and diminished over time. Changes in vitamin D intake over time might have contributed to the diminished association observed in later years. Vitamin D intake of >800 IU/day appears to be associated with a small decrease in risk of breast cancer among postmenopausal women. Studies evaluating all sources of vitamin D, especially sun exposure, are needed to fully understand the association between vitamin D and breast cancer risk.

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    • "In contrast, a study involving 1,019 incident cases within the prospective Women’s Health Study (Lin et al. 2007) and another study involving 2,855 incident cases within the prospective Cancer Prevention Study II Nutrition Cohort (McCullough et al. 2005) reported stronger negative associations between dietary vitamin D intake and both ER+ or PR+ tumors. However, a study of 2,440 incident cases within the prospective Iowa Women’s Health Study observed stronger negative associations with ER– or PR– tumors (Robien et al. 2007). In vitro studies suggest that ER+ breast cancer cell lines are generally more sensitive than ER– cell lines to 1,25(OH)2D–mediated growth regulation (Welsh et al. 2002). "
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    ABSTRACT: Epidemiologic evidence suggests a negative relation between sunlight exposure and breast cancer risk. The hypothesized mechanism is sunlight-induced cutaneous synthesis of vitamin D. To examine sun exposure and its interaction with vitamin D receptor (VDR) gene variants on breast cancer risk. We examined sun exposure and breast cancer incidence among 31,021 private pesticide applicators' wives, including 578 cases, enrolled in the prospective Agricultural Health Study cohort and followed 8.6 years on average. We estimated interactions between sun exposure, VDR variants, and breast cancer in a nested case-control study comprising 293 cases and 586 matched controls. Information on sun exposure was obtained by questionnaire at cohort enrollment. Relative risks were estimated using Cox proportional hazards regression for the cohort data and conditional logistic regression for the nested case-control data. A small decrease in breast cancer risk was observed in association with usual sun exposure ≥ 1 hour per day (versus < 1 hour per day) ten years before the start of follow-up among all participants (HR = 0.8; 95% CI: 0.6, 1.0). The association appeared slightly stronger in relation to estrogen receptor-positive tumors (HR = 0.7; 95% CI: 0.5, 0.9) than estrogen receptor-negative tumors (HR = 1.1; 95% CI: 0.6, 2.1). The HR for joint exposure ≥ 1 hour per day of sunlight and one VDR haplotype was less than expected given negative HRs for each individual exposure (interaction p-value = 0.07). These results suggest that sun exposure may be associated with reduced risk of breast cancer, but we did not find clear evidence of modification by VDR variants. Larger studies are warranted, particularly among populations in which low levels of usual sun exposure can be more precisely characterized.
    Environmental Health Perspectives 11/2013; 122(2). DOI:10.1289/ehp.1206274 · 7.98 Impact Factor
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    • "Studies with both pre- and postmenopausal female populations have shown high prevalence of vitamin D deficiency despite supplementation.[1718] Premenopausal females had slightly more low mean serum levels of vitamin D compared to the postmenopausal females and the results yielded minimum significance. "
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    ABSTRACT: The aim was to determine serum vitamin D levels in breast cancer patients and to assess its risk association with grade and stage of the tumor. Ninety breast cancer patients and equal number of age-matched healthy females were recruited into the study by consecutive sampling over a period of 6 months for this case control study. Serum 25(OH)2D levels and CT bone mineral density was done. The mean age was 46±1.5 years. Age, marital status, menopausal, residential area, parda observing status, and body mass index were similar in distribution among cases and controls. The mean serum vitamin D level in the breast cancer patients was 9.3 ng/ml and in the control group was 14.9 ng/ml (P value <0.001). Vitamin D deficiency was seen in 95.6% (86) breast cancer patients and in 77% (69) of the control group (P value <0.001). Among the breast cancer patients the tumor characteristics (histology, grade, stage, and receptor status) did not show any significant associations with serum levels of vitamin D. Premenopausal breast cancer females had a mean serum vitamin D level of 10.5 ng/ml and postmenopausal females had a mean value of 13.5 ng/ml (P value 0.015). Low BMD did not correlate significantly with vitamin D deficiency (P value 0.787). Invariably almost all patients with breast cancer were vitamin D deficient. Tumor characteristics did not show any significant associations with serum levels of vitamin D. Bone mineral density did not correlate significantly with vitamin D deficiency.
    05/2012; 16(3):409-13. DOI:10.4103/2230-8210.95684
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    • "Six studies of oral intake of vitamin D that found an inverse association with risk of breast cancer in humans,9-13,37 although there were four that individually did not detect a statistically significant association.38-41 "
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    ABSTRACT: A wide range of epidemiologic and laboratory studies combined provide compelling evidence of a protective role of vitamin D on risk of breast cancer. This review evaluates the scientific evidence for such a role in the context of the A.B. Hill criteria for causality, in order to assess the presence of a causal, inverse relationship, between vitamin D status and breast cancer risk. After evaluation of this evidence in the context of Hill's criteria, it was found that the criteria for a causal relationship were largely satisfied. Studies in human populations and the laboratory have consistently demonstrated that vitamin D plays an important role in the prevention of breast cancer. Vitamin D supplementation is an urgently needed, low cost, effective, and safe intervention strategy for breast cancer prevention that should be implemented without delay. In the meantime, randomized controlled trials of high doses of vitamin D(3) for prevention of breast cancer should be undertaken to provide the necessary evidence to guide national health policy.
    Dermato-Endocrinology 04/2012; 4(2):152-7. DOI:10.4161/derm.20449
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