Table 5.

Effect modification of serum retinol, retinyl palmitate, and the retinyl palmitate/retinol ratio on the association of serum 25(OH)D concentrations with lung cancer risk

		Serum 25(OH)D concentrations				P-interaction
		Q1	Q2	Q3	Q4
All lung cancer1
Serum retinol
Below median (<66 μg/dL)	N, case/control	39/44	30/37	34/27	27/34	0.80
	OR (95% CI)	1.00 (Referent)	0.92 (0.48-1.78)	1.44 (0.72-2.86)	0.98 (0.47-2.04)
Above median (≥66 μg/dL)	N, case/control	25/29	44/38	50/48	49/41
	OR (95% CI)	0.97 (0.46-2.02)	1.41 (0.70-2.82)	1.19 (0.65-2.20)	1.41 (0.72-2.76)
Serum retinyl palmitate
Below median (<3.0 μg/dL)	N, case/control	37/51	33/40	26/28	23/32	0.80
	OR (95% CI)	1.00 (Referent)	1.11 (0.57-2.16)	1.25 (0.62-2.54)	1.03 (0.51-2.06)
Above median (≥3.0 μg/dL)	N, case/control	27/22	41/35	58/47	53/43
	OR (95% CI)	1.77 (0.83-3.75)	1.74 (0.91-3.36)	1.74 (0.96-3.17)	1.75 (0.92-3.35)
Serum retinyl palmitate/retinol ratio
Below median (<0.05)	N, case/control	39/47	38/41	37/39	31/37	0.81
	OR (95% CI)	1.00 (Referent)	1.18 (0.61-2.29)	1.17 (0.61-2.24)	1.14 (0.59-2.21)
Above median (≥0.05)	N, case/control	25/26	36/34	47/36	45/38
	OR (95% CI)	1.22 (0.61-2.46)	1.35 (0.70-2.60)	1.64 (0.88-3.08)	1.51 (0.76-3.00)
Non-small cell lung cancer2
Serum retinol
Below median (<66 μg/dL)	N, case/control	26/44	18/37	21/27	13/34	0.43
	OR (95% CI)	1.00 (Referent)	0.84 (0.39-1.83)	1.23 (0.56-2.68)	0.68 (0.29-1.58)
Above median (≥66 μg/dL)	N, case/control	17/29	31/38	33/48	32/41
	OR (95% CI)	0.95 (0.43-2.11)	1.37 (0.67-2.81)	1.16 (0.57-2.34)	1.37 (0.66-2.82)
Serum retinyl palmitate
Below median (<3.0 μg/dL)	N, case/control	28/51	21/40	15/28	11/32	0.30
	OR (95% CI)	1.00 (Referent)	0.94 (0.45-1.98)	0.95 (0.42-2.15)	0.66 (0.28-1.58)
Above median (≥3.0 μg/dL)	N, case/control	15/22	28/35	39/47	34/43
	OR (95% CI)	1.16 (0.50-2.71)	1.49 (0.73-3.05)	1.47 (0.75-2.91)	1.52 (0.76-3.07)
Serum retinyl palmitate/retinol ratio
Below median (<0.05)	N, case/control	30/47	26/41	23/39	14/37	0.06
	OR (95% CI)	1.00 (Referent)	0.94 (0.46-1.91)	0.86 (0.41-1.78)	0.62 (0.28-1.39)
Above median (≥0.05)	N, case/control	13/26	23/34	31/36	31/38
	OR (95% CI)	0.69 (0.30-1.59)	1.07 (0.51-2.22)	1.29 (0.64-2.63)	1.30 (0.64-2.65)
Adenocarcinoma2
Serum retinol
Below median (<66 μg/dL)	N, case/control	23/44	16/37	19/27	11/34
	OR (95% CI)	1.00 (Referent)	0.84 (0.36-1.82)	1.26 (0.56-2.82)	0.66 (0.27-1.61)	0.44
Above median (≥66 μg/dL)	N, case/control	16/29	27/38	31/48	28/41
	OR (95% CI)	1.03 (0.46-2.32)	1.35 (0.64-2.08)	1.25 (0.61-2.57)	1.42 (0.67-3.01)
Serum retinyl palmitate
Below median (<3.0 μg/dL)	N, case/control	25/51	16/40	12/28	11/32	0.40
	OR (95% CI)	1.00 (Referent)	0.77 (0.35-1.70)	0.80 (0.33-1.91)	0.73 (0.30-1.77)
Above median (≥3.0 μg/dL)	N, case/control	14/22	26/35	38/47	28/43
	OR (95% CI)	1.13 (0.47-2.70)	1.53 (0.74-3.19)	1.61 (0.80-3.22)	1.44 (0.69-2.99)
Serum retinyl palmitate/retinol ratio
Below median (<0.05)	N, case/control	27/47	22/41	20/39	13/37	0.06
	OR (95% CI)	1.00 (Referent)	0.85 (0.41-1.77)	0.79 (0.37-1.69)	0.63 (0.28-1.46)
Above median (≥0.05)	N, case/control	12/26	20/34	30/36	26/38
	OR (95% CI)	0.67 (0.28-1.58)	1.03 (0.48-2.20)	1.41 (0.68-2.90)	1.25 (0.60-2.62)

¹Odds ratios were estimated by conditional logistic regression, adjusted for matching factors (age and study status), race/ethnicity, BMI, CaD Trial allocation, and season of blood draw.

²Odds ratios were estimated by unconditional logistic regression, adjusted for the covariates and matching factors (age and CT/OS status).