Table 4. Survival time-stratified association between season-specific quintile of serum 25(OH)D at baseline and mortality among men diagnosed with prostate cancer, ATBC Study.

	Survived <3.3 years		Survived ≥3.3 years
Season-Specific Quintile of Serum 25(OH)D	# Prostate Cancer Deaths	HR (95% CI)*	# Deaths	HR (95% CI)*
Q1	34	1.0 (ref)	35	1.0 (ref)
Q2	36	0.81 (0.51 – 1.30)	43	0.87 (0.55 – 1.36)
Q3	36	0.84 (0.52 – 1.34)	40	0.61 (0.38 – 0.96)
Q4	30	0.72 (0.44 – 1.18)	25	0.39 (0.23 – 0.66)
Q5	45	0.95 (0.61 – 1.50)	38	0.53 (0.34 – 0.85)
p-trend		0.53		0.0002

^*Adjusted for age at prostate cancer diagnosis, cigarettes smoked per day, physical activity, and family history of prostate cancer