Environment and Breast Cancer: Science Review

Evidence From Humans
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Vitamin D and breast cancer risk: the NHANES I Epidemiologic follow-up study, 1971-1975 to 1992. National Health and Nutrition Examination Survey
John, E. M., Schwartz, G. G., Dreon, D. M., Koo, J. Cancer Epidemiol Biomarkers Prev. 1999. 8:5, 399-406.
Topic area
Diet - Sun exposure
Study design
Prospective cohort
Funding agency
DOD and Northern California cancer Center's Fashio
Study Participants
Menopausal Status
The menopausal status of women included in this study is listed here.
Postmenopausal and premenopausal combined
Number in Cohort
Cohort 4,747
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
In: Women aged 25-74 who were traced and/or participated in at least one of the four follow-up surveys of the NHANES I. Ex: Women with a personal history of cancer, women without dietary or dermatologic data, non-white women, women with ambiguous information on personal history of breast cancer, pregnant or breast feeding women at baseline, or pregnant during the 3 months preceding the baseline interview.
Comment about participation selection
Long and rigorous follow-up, small sample, self-reported breast cancer
Exposure Investigated
Exposures investigated
Vitamin D, dietary
How exposure was measured
Questionnaire, in person
Exposure assessment comment
Dietary analysis limited to a 24-h recall data
Statistical Analysis
Ethnic groups with separate analysis
If this study provided a separate analysis by ethnic or racial group, the groups are listed here.
Only white
Confounders considered
Other breast cancer risk factors, such as family history, age at first birth, and hormone replacement therapy use, that were taken into account in the study.
Not considered: Parity, family history of breast cancer
Genetic characterization included
If the study analyzed relationships between environmental factors and inherited genetic variations, this field will be marked “Yes.” “No”, if not.
Description of major analysis
Adjusted RR with 95% CI, highest versus lowest tertile of vitamin D intake, stratification by sun exposure, mean follow-up 17.3 years
Results Comments
The average intake of vitamin D from food was slightly lower among breast cancer cases than non-cases. The difference however was not significant.
Author address
Northern California Cancer Center, Union City 94587, USA. ejohn@nccc.org