Vitamin D intake and breast cancer risk in postmenopausal women: The Iowa Women's Health Study
ABSTRACT 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.
- SourceAvailable from: Bettina Toth
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- "However, in contrast to other studies (Clark et al. 1983; Mason et al. 1983; Howat et al. 1985), we were unable to demonstrate prognostic relevance for ER/PR expression, which might be due to the inclusion of the small number of patients. Data of vitamin D intake and breast cancer incidence or prognosis still showed heterogeneous results for postmenopausal patients (Robien et al. 2007; Chlebowski et al. 2008). The data also differed from results of premenopausal women (Lin et al. 2007 "
ABSTRACT: In this study, we analyzed vitamin D receptor (VDR) expression and survival in a breast cancer patient cohort of 82 breast cancer patients. Immunohistochemical analysis was possible in 91.5% of the patients (75/82). Staining was evaluated using the semi-quantitative assay according to Remmele and Stegner (immunoreactivity score [IRS]). IRS 0-1 was negative/very low, IRS 2-4 was moderate to high, and IRS 6-12 was high. Statistical analysis was performed by Spearman's correlation test (p<0.05 significant). Overall survival was analyzed using Kaplan-Meier estimations. Only 6 patients had a negative IRS. Moderate IRS values were present in 20 patients. Most of the patients had a high IRS (49). For survival analysis, data were dichotomized (IRS 0-4: negative to moderate and IRS 6-12: high VDR expression). In univariate analysis, VDR expression showed significant differences in progression-free survival (PFS) and overall survival (OS). Patients with high IRS scores showed significantly better PFS and OS than patients with moderate/negative IRS scores for VDR expression. Tumor size was significantly correlated to PFS. When analyzed separately, the three different IRS groups showed significant differences in VDR expression. The present data suggest that VDR expression in breast cancer tissue may be of clinical significance, and the results provide evidence that VDR may be a factor with prognostic relevance.Journal of Histochemistry and Cytochemistry 11/2011; 60(2):121-9. DOI:10.1369/0022155411429155 · 2.40 Impact Factor
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- "However, a cohort study that monitored over 74 000 Japanese adults over a 7.8-year period found no statistical association between vitamin D intakes and incidence of colorectal cancer, although an inverse trend was evident (Ishihara et al. 2008). Turning to breast cancer, another area where new studies have arisen, a prospective study of more than 34 000 post-menopausal women found an 11% reduction in breast cancer risk when vitamin D intakes were >20 mg/day (Robien et al. 2007). A large case-control study (Abbas et al. 2008) found significantly lower risks of breast cancer (43%–69% lower) when serum 25(OH)D was >30 nmol/l, although another casecontrol study failed to find such an association (Freedman et al. 2007). "
ABSTRACT: Increasingly, scientists are debating whether photochemical synthesis of vitamin D in Western countries is adequate, and whether dietary intakes can plug the gap between endogenous vitamin D production and requirements, particularly in young and older populations. The debate is driven by the plethora of evidence suggesting that, in addition to its important role in maintaining bone health, vitamin D may be involved in ameliorating cell ageing and preventing cardiovascular disease, diabetes, immune dysfunction and some cancers. Observational evidence from different populations suggests a significant degree of vitamin D insufficiency, often defined as plasma 25-hydroxyvitamin D [25(OH)D] <25 nmol/l. Some experts have argued that daily intakes up to 40 µg/day may be needed to ensure a desirable vitamin D status, even after accounting for sun exposure. However, there is presently no consensus on the most appropriate vitamin D status for maintaining bone health and preventing chronic disease. In addition, the UK has not set a vitamin D recommendation for most adults under 65 years. Given the plethora of information about vitamin D and bone health, this article reviews evidence for a link between vitamin D and other aspects of health. In conclusion, three actions are suggested: (1) agreement on optimal plasma 25(OH)D levels for health; (2) a debate on whether UK dietary recommendations need revision; and (3) better promotion of dietary vitamin D via food sources and, for certain groups, supplements.Nutrition Bulletin 05/2009; 34(2):185 - 197. DOI:10.1111/j.1467-3010.2009.01755.x
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