Table 3. Crude and adjusted OR and 95% CI for the associations between serum 25(OH) vitamin D concentration and risk of incident liver cancer in the case–control set nested in the Nutrition Intervention Trials cohort.

	Continuousa		Quartileb
			Q1 (n=266)c		Q2 (n=265)c			Q3 (n=266)c			Q4 (n=265)c
	OR	95% CI	n	OR (Reference)	n	OR	95% CI	n	OR	95% CI	n	OR	95% CI	Ptrend	Pinteraction
Crude	1.00	0.94–1.06	63	1.00	55	0.88	0.59– 1.31	57	0.91	0.61–1.35	51	0.81	0.54–1.22	0.365	—
Age- and sex-adjusted	0.98	0.92–1.04	—	1.00	—	0.88	0.59–1.31	—	0.90	0.61–1.35	—	0.81	0.54–1.21	0.352	—
Fully adjustedd	0.95	0.88–1.03	—	1.00	—	0.91	0.60–1.37	—	0.87	0.57–1.31	—	0.74	0.47–1.18	0.208	—
Women	0.95	0.81–1.11	28	1.00	19	0.75	0.39–1.42	26	0.94	0.51–1.73	18	0.69	0.34–1.39	0.421	0.617
Men	0.95	0.87–1.05	35	1.00	36	1.02	0.59–1.77	31	0.81	0.46–1.44	33	0.79	0.42–1.48	0.338
Age at baseline
<55	0.94	0.84–1.05	31	1.00	23	0.77	0.41–1.43	32	0.96	0.54–1.72	24	0.73	0.37–1.44	0.538	0.997
⩾55	0.97	0.88–1.08	32	1.00	32	1.11	0.63–1.93	25	0.79	0.44–1.44	27	0.80	0.42–1.53	0.349
Season of blood draw
January–May	0.97	0.89–1.06	62	1.00	53	0.90	0.60–1.37	50	0.85	0.56–1.30	32	0.81	0.50–1.31	0.345	0.703
August–September	0.88	0.75–1.04	1	1.00	2	0.86	0.05–14.62	7	0.64	0.06–7.36	19	0.32	0.03–3.61	0.109
Follow-up years
<7	0.95	0.84–1.08	14	1.00	16	1.27	0.59–2.74	14	0.88	0.40–1.96	18	0.86	0.36–2.05	0.576	0.989
⩾7 to <14	0.96	0.85–1.09	22	1.00	18	0.90	0.47–1.75	16	0.78	0.39–1.54	15	0.79	0.37–1.67	0.447
⩾14	0.95	0.84–1.08	27	1.00	21	0.77	0.42–1.43	27	0.93	0.52–1.67	18	0.64	0.32–1.28	0.327
HBV/HCV seroposivity
HBV+	0.97	0.89–1.05	43	1.00	37	0.85	0.53–1.36	40	0.90	0.56–1.44	37	0.79	0.47–1.32	0.425	0.442
HCV+	0.82	0.63–1.06	4	1.00	9	2.02	0.60–6.79	8	1.56	0.45–5.41	3	0.39	0.07–2.15	0.331	0.634
Neither	0.98	0.86–1.12	18	1.00	17	0.97	0.49–1.93	15	0.86	0.42–1.76	14	0.80	0.36–1.76	0.538	—
Calcium
<1.485 mmol l−1	1.02	0.93–1.13	26	1.00	24	1.10	0.60–2.04	32	1.28	0.71–2.28	25	1.14	0.61–2.13	0.561	0.047
⩾1.485 mmol l−1	0.88	0.78–0.98	37	1.00	31	0.77	0.44–1.35	25	0.55	0.30–1.02	26	0.43	0.21–0.89	0.014
Trial
Dysplasia Trial	0.88	0.75–1.05	1	1.00	2	0.82	0.05–14.06	7	0.64	0.06–7.30	19	0.32	0.03–3.63	0.119	0.414
General Population Trial	0.95	0.86–1.04	62	1.00	53	0.83	0.54–1.26	50	0.75	0.52–1.10	32	0.69	0.42–1.15	0.127

Abbreviations: BMI=body mass index; CI= confidence interval; HBcAg=hepatitis B core antigen; HBsAg=hepatitis B surface antigen; HBV=hepatitis B virus; HCsAg=hepatitis C surface antigen; HCV=hepatitis C virus; OR= odds ratio.

^aORs for continuous vitamin D were scaled to one-half the interquartile range (7.9 nmol l^–1).

^bWe used sex-specific cutoff values to calculate relative risks. Quartile for women: <11.17, ⩾11.17 to <14.86, ⩾14.86 to <21.80, ⩾21.80 (nmol l^–1); and quartile for men: <18.14, ⩾18.14 to <25.33, ⩾25.33 to <38.84, ⩾38.84 (nmol l^–1).

^cNumber of subjects in the control group.

^dAdjusted for age at baseline, sex, smoking, drinking, BMI, season of blood draw, HBsAg, HBcAg and HCsAg. The bold entries are considered statistically significant.