Vitamin and Mineral Supplement Use Is Associated with Reduced Risk of Prostate Cancer

Alan R. Kristal; Janet L. Stanford; Jennifer H. Cohen; Kristine Wicklund; Ruth E. Patterson

DOI: Published October 1999

Article Figures & Data

Tables

Table 1

Demographic and health-related characteristics of cases and controls

	Cases (n = 697) (%)	Controls (n = 666) (%)
Age (yr)
40–49	5.7	8.1
50–54	19.7	18.9
55–59	34.6	38.3
60–64	40.0	34.7
Race
White	94.8	97.9
Black	5.2	2.1
Family history of prostate cancer
No family history	72.5	84.5
1^st degree	18.9	9.8
2^nd degree only	8.6	5.7
Education (yr)
<12	27.7	23.4
13–15	21.5	22.8
16	26.8	27.3
17+	24.0	26.4
Body mass index (kg/m²)
≤23	23.5	21.5
24–26	37.4	34.7
27–29	22.1	24.9
≥30	16.9	18.9
PSA tests within previous 5 yr
None	28.7	67.3
1–2	34.0	19.2
3–4	19.8	8.1
≥5	17.5	5.4
Stage at diagnosis		NA^a
A	15.2
B	57.0
C	17.4
D	7.7
Unknown	2.7

^a NA, not applicable.

Table 2

Distribution of vitamin and mineral supplement use in cases and controls

Supplement (frequency/week)	Cases (n = 697) (%)	Controls (n = 666) (%)
Multivitamin
0	54.5	55.7
<1/week	5.6	5.1
1–6/week	9.5	12.5
≥7/week	30.4	26.7
Vitamin C
0	62.3	58.7
<1/week	6.2	7.7
1–6/week	10.6	11.7
≥7/week	20.9	21.9
Vitamin E
0	77.6	76.4
<1/week	3.0	3.5
1–6/week	6.2	5.7
≥7/week	13.2	14.4
Zinc
0	92.4	90.5
<1/week	2.0	2.0
1–6/week	2.3	2.6
≥7/week	3.3	5.0
Calcium
0	90.7	91.9
<1/week	1.0	1.2
1–6/week	2.4	2.3
≥7/week	5.9	4.7
Vitamin A
0	92.8	92.0
<1/week	1.1	1.2
1–6/week	2.7	1.8
≥7/week	3.3	5.0
Iron
0	96.4	96.7
<1/week	1.3	1.7
1–6/week	1.6	0.6
≥7/week	0.7	1.1

Table 3

Odds ratios of prostate cancer associated with use of vitamin and mineral supplements

Supplement (frequency/week)	Unadjusted odds ratio (95% confidence limits)	Adjusted odds ratio^a (95% confidence limits)	P value for trend	Adjusted odds ratio^a (95% confidence limits), supplement^b users only
Multivitamin
0	1.00	1.00
<1/week	1.12 (0.69, 1.82)	1.15 (0.67, 1.98)	0.468
1–6/week	0.78 (0.54, 1.10)	0.69 (0.46, 1.02)
≥7/week	1.16 (0.91, 1.49)	0.96 (0.73, 1.26)
Vitamin C
0	1.00	1.00		1.00
<1/week	0.76 (0.49, 1.16)	0.73 (0.45, 1.17)	0.071	0.62 (0.32, 1.19)
1–6/week	0.86 (0.60, 1.21)	0.83 (0.56, 1.22)		0.70 (0.39, 1.26)
≥7/week	0.90 (0.69, 1.18)	0.77 (0.57, 1.04)		0.64 (0.37, 1.11)
Vitamin E
0	1.00	1.00		1.00
<1/week	0.86 (0.47, 1.57)	1.12 (.057, 2.20)	0.118	1.17 (0.59, 2.34)
1–6/week	1.10 (0.68, 1.68)	0.85 (0.51, 1.41)		0.93 (0.55, 1.59)
≥7/week	0.90 (0.66, 1.23)	0.76 (0.54, 1.08)		0.86 (0.57, 1.28)
Zinc
0	1.00	1.00		1.00
<1/week	1.00 (0.47, 2.19)	0.73 (0.31, 1.71)	0.038	0.82 (0.35, 1.92)
1–6/week	0.88 (0.44, 1.77)	0.79 (0.36, 1.72)		0.81 (0.37, 1.76)
≥7/week	0.65 (0.38, 1.11)	0.55 (0.30, 1.00)		0.59 (0.32, 1.09)
Calcium
0	1.00	1.00		1.00
<1/week	0.85 (0.30, 2.37)	0.67 (0.22, 2.04)	0.866	0.83 (0.27, 2.49)
1–6/week	1.10 (0.54, 2.24)	1.13 (0.52, 2.45)		1.23 (0.56, 2.70)
≥7/week	1.28 (0.80, 2.08)	1.04 (0.61, 1.78)		1.25 (0.73, 2.17)
Vitamin A
0	1.00	1.00		1.00
<1/week	0.95 (0.35, 2.59)	1.05 (0.34, 3.18)	0.244	1.16 (0.39, 3.46)
1–6/week	1.50 (0.73, 3.20)	1.46 (0.66, 3.30)		1.56 (0.71, 3.55)
≥7/week	0.66 (0.38, 1.13)	0.59 (0.32, 1.06)		0.67 (0.37, 1.22)
Iron
0	1.00	1.00		1.00
<1/week	0.78 (0.31, 1.91)	0.52 (0.20, 1.33)	0.700	0.60 (0.23, 1.55)
1–6/week	2.64 (0.90, 9.55)	2.74 (0.82, 10.8)		2.80 (0.85, 10.93)
≥7/week	0.69 (0.20, 2.16)	0.50 (0.13, 1.76)		0.55 (0.15, 1.91)

^a Controlled for fat, energy, race, age, family history of prostate cancer, body mass index, PSA tests in previous 5 years, and education.
^b Users of at least one type of single supplement: n = 312 cases, n = 308 controls.