Table 3.

Tertiles of 25OHD₃, PTH and Ca in relation to breast cancer mortality

Analyte	Tertile	Range	Numbers within tertile	Person-years	Dead breast cancer	Breast cancer mortality/100,000	HRa	HRb	HRc
25OHD3 (nmol/L)	1	≤75	221	1,879	39	2,076	1.84 (1.08–3.13)	2.04 (1.19–3.51)	2.46 (1.38–4.37)
	2	76–99	216	1,863	21	1,127	1	1	1
	3	≥100	218	1,911	39	2,041	1.81 (1.06–3.07)	1.78 (1.05–3.04)	1.99 (1.14–3.49)
							p trend: 0.95	p trend: 0.62	p trend: 0.51
PTH (pmol/L)	1	≤2.95	223	1,842	36	1,954	1.31 (0.81–2.12)	1.32 (0.81–2.14)	0.98 (0.53–1.65)
	2	2.96–4.41	220	2,000	30	1,500	1	1	1
	3	≥4.42	221	1,904	34	1,786	1.20 (0.73–1.96)	1.21 (0.74–1.98)	0.86 (0.51–1.47)
							p trend: 0.71	p trend: 0.70	p trend: 0.62
Calcium (mmol/L)	1	≤2.36	235	2,067	38	1,838	1	1	1
	2	2.37–2.43	224	1,932	33	1,707	0.93 (0.58–1.48)	0.90 (0.56–1.44)	0.80 (0.48–1.34)
	3	≥2.44	202	1,727	28	1,622	0.88 (0.54–1.44)	0.82 (0.50–1.34)	0.53 (0.30–0.92)
							p trend: 0.61	p trend: 0.40	p trend: 0.02

^aCrude analysis

^bAdjusted for season and year of blood sample, and age at baseline

^cAdjusted for same factors as ^b but also for age at diagnosis, size of tumor, Elston–Ellis grade, histological type, ER status, PGR status, lymph node status and distant metastasis at diagnosis