Predicted 25-hydroxyvitamin D in relation to incidence of breast cancer in a large cohort of African American women

Table 2 Cumulative predicted vitamin D status in relation to breast cancer incidence, overall and by estrogen receptor (ER) status of the breast tumor

Predicted 25(OH)D (quartiles)	Breast cancer cases	Person-years	Age + period IRR	95 % CI	MV IRR^a	95 % CI	P trend
All cases
4 (highest)	338	183,614	1.00	Ref	1.00	Ref	0.015
3	351	183,625	1.02	0.88, 1.19	1.08	0.93, 1.26
2	365	183,603	1.02	0.88, 1.18	1.12	0.95, 1.31
1 (lowest)	400	183,568	1.06	0.92, 1.23	1.23	1.04, 1.46
ER- cases
4 (highest)	109	183,326	1.00	Ref	1.00	Ref	0.42
3	100	183,346	0.90	0.68, 1.18	0.94	0.71, 1.25
2	109	183,336	0.93	0.71, 1.21	1.02	0.77, 1.36
1 (lowest)	115	183,324	0.94	0.72, 1.22	1.12	0.82, 1.52
ER+ cases
4 (highest)	182	183,430	1.00	Ref	1.00	Ref	0.035
3	192	183,446	1.05	0.86, 1.29	1.12	0.91, 1.38
2	215	183,403	1.13	0.93, 1.38	1.25	1.01, 1.55
1 (lowest)	213	183,415	1.08	0.88, 1.32	1.26	1.00, 1.58

^aAdjusted for age (continuous), family history of breast cancer, age at menarche, age at menopause, parity, age at first birth, oral contraceptive use, body mass index, and use of estrogen and progesterone female hormones
25(OH)D 25-hydroxyvitamin D, IRR incident rate ratio, MV multivariate model, CI Confidence interval

ISSN: 1465-542X