Plasma 25-hydroxyvitamin D3 is associated with decreased risk of postmenopausal breast cancer in whites: a nested case–control study in the multiethnic cohort study
Background: Higher sunlight exposure is correlated with lower incidence of breast cancer in ecological studies, but
findings from prospective studies regarding the association of circulating levels of vitamin D with the risk of breast
cancer have been null. The objective of this study was to examine the relation between plasma levels of vitamin D
and the risk of postmenopausal breast cancer.
Methods: We conducted a nested case–control study within the Multiethnic Cohort Study of five race/ethnic
groups (white, African-American, Native Hawaiian, Japanese, and Latino) from Hawaii and Los Angeles between
2001 and 2006. Pre-diagnostic plasma levels of 25-hydroxyvitamin D2 [25(OH)D2], 25-hydroxyvitamin D3 [25(OH)D3]
and 25(OH)D (sum of 25(OH)D2 and 25(OH)D3) were examined among 707 postmenopausal breast cancer cases
and matched controls.
Results: Using conditional logistic regression models, 20 ng/mL increases of plasma 25(OH)D3 (odds ratio (OR) 0.28;
95% confidence interval (CI) 0.14-0.56) and 25(OH)D (OR 0.43; 95% CI 0.23-0.80) were inversely associated with
breast cancer risk among white women, but not among women in other race/ethnic groups. Using twosegmented,
piecewise-linear logistic regression models, the change-points of the ORs, either for 25(OH)D3 or for 25
(OH)D, were detected as 20 ng/mL among whites.
Conclusions: Circulating 25(OH)D3 and 25(OH)D were associated with a reduced risk of postmenopausal breast
cancer among whites, but not in other ethnic groups, who reside in low latitude regions.
Keywords: Breast cancer, 25-Hydroxyvitamin D3, 25-Hydroxyvitamin D2, Ethnic groups, Nested case–control study
Yeonju Kim1, Adrian A Franke2, Yurii B Shvetsov1, Lynne R Wilkens1, Robert V Cooney3, Galina Lurie1,
Gertraud Maskarinec1, Brenda Y Hernandez1, Loïc Le Marchand1, Brian E Henderson4, Laurence N Kolonel1
and Marc T Goodman BMC Cancer. 2014 Jan 17;14:29. doi: 10.1186/1471-2407-14-29.