האם ויטמין D הוא תרופת פלא לסרטן?

רמה גבוהה של ויטמין D מעלה ב 70% את הסיכון לסרטן הוושט בגברים. Br J Cancer. 2007 Jun 5 Prospective study of serum 25(OH)-vitamin D concentration AND risk of oesophageal AND gastric cancers. . We prospectively examined the relation between pretrial serum vitamin D status AND risk of oesophageal AND gastric cancers among subjects who developed cancer over 5.25 years of follow-up, including 545 oesophageal squamous cell carcinomas (ESCC), 353 gastric cardia adenocarcinomas, 81 gastric noncardia adenocarcinomas, AND an age- AND sex-stratified random sample of 1105 subjects. The distribution of serum 25(OH)D was calculated using the known sampling weights. For the cohort as a whole, the 25th, 50th, AND 75th percentile concentrations of 25(OH)-vitamin D were 19.6, 31.9, AND 48.7 nmol l(-1), respectively, AND we found that higher serum 25(OH)D concentrations were associated with monotonically increasing risk of ESCC in men, but not in women. Comparing men in the fourth quartile of serum 25(OH)D concentrations to those in the first, we found a hazard ratio (HR) (95% confidence interval (CI)) of 1.77 (1.16-2.70), P trend=0.0033. The same comparison in women had a HR (95% CI) of 1.06 (0.71-1.59), P trend=0.70. We found no associations for gastric cardia OR noncardia adenocarcinoma. Among subjects with low vitamin D status, higher serum 25(OH)D concentrations were associated with significantly increased risk of ESCC in men, but not in women. Further refinements of the analysis did not suggest any factors, which could explain this unexpected result. ******************************************************************************** ויטמין D מפחית במעט את הסיכון לסרטו שד Cancer Causes Control. 2007 Jun 5 Vitamin D intake AND breast cancer risk in postmenopausal women: the Iowa Women's Health Study. 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. ********************************************************************************* Arch Intern Med. 2007 May 28;167(10):1050-9. Intakes of calcium AND vitamin d AND breast cancer risk in women. BACKGROUND: Animal data suggest the potential anticarcinogenic effects of calcium AND vitamin D on breast cancer development. However, epidemiologic data relating calcium AND vitamin D levels to breast cancer have been inconclusive. METHODS: We prospectively evaluated total calcium AND vitamin D intake in relation to breast cancer incidence among 10 578 premenopausal AND 20 909 postmenopausal women 45 years OR older who were free of cancer AND cardiovascular disease at baseline in the Women's Health Study. Baseline dietary intake was assessed by a food frequency questionnaire. We used Cox proportional hazards regression to estimate hazard ratios AND 95% confidence intervals. RESULTS: During an average of 10 years of follow-up, 276 premenopausal AND 743 postmenopausal women had a confirmed diagnosis of incident invasive breast cancer. Higher intakes of total calcium AND vitamin D were moderately associated with a lower risk of premenopausal breast cancer; the hazard ratios in the group with the highest relative to the lowest quintile of intake were 0.61 (95% confidence interval, 0.40-0.92) for calcium (P = .04 for trend) AND 0.65 (95% confidence interval, 0.42-1.00) for vitamin D intake (P = .07 for trend). The inverse association with both nutrients was also present for large OR poorly differentiated breast tumors among premenopausal women (P</=.04 for trend). By contrast, intakes of both nutrients were not inversely associated with the risk of breast cancer among postmenopausal women. CONCLUSIONS: Findings from this study suggest that higher intakes of calcium AND vitamin D may be associated with a lower risk of developing premenopausal breast cancer. The likely apparent protection in premenopausal women may be more pronounced for more aggressive breast tumors. ************************************************************************************* Cancer. 2007 Jun 15;109(S12):2712-2749. Diet AND breast cancer: a review of the prospective observational studies The role of diet for the risk of breast cancer is of great interest as a potentially modifiable risk factor. The evidence from prospective observational studies was reviewed AND summarized on selected dietary factors, gene-diet interactions, AND breast cancer incidence. Dietary factors were considered that, based on their nutritional constituents, are of particular interest in the context of breast cancer: fat intake, biomarkers of fat intake, fruit AND vegetable consumption, antioxidant vitamins (vitamins A, C, E, AND beta-carotene), serum antioxidants, carbohydrate intake, glycemic index AND glycemic load, dairy consumption (including vitamin D), consumption of soy products AND isoflavones, green tea, heterocyclic amines, AND adolescent diet. The PubMed database was searched for all prospective studies that relate these dietary items to the incidence of breast cancer OR consider gene-diet interactions. Among the prospective epidemiologic studies conducted on diet AND breast cancer incidence AND gene-diet interactions AND breast cancer incidence, to date there is no association that is consistent, strong, AND statistically significant, with the exception of alcohol intake, overweight, AND weight gain. The apparent lack of association between diet AND breast cancer may reflect a true absence of association between diet AND breast cancer incidence OR may be due to measurement error exceeding the variation in the diet studied, lack of sufficient follow-up, AND focus on an age range of low susceptibility. The risk of breast cancer can be reduced by avoidance of weight gain in adulthood AND limiting the consumption of alcohol.