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. Author manuscript; available in PMC: 2015 May 1.
Published in final edited form as: JAMA Ophthalmol. 2014 May;132(5):549–559. doi: 10.1001/jamaophthalmol.2014.100

Table 5.

Quintiles of vitamin B12 intake in relation to the risks of exfoliation glaucoma / glaucoma suspect in NHS (1980-2010) and in HPFS (1986-2010)

Quintiles of vitamin B12
SOURCE Total Vitamin B12 * Q1 Q2 Q3 Q4 Q5 p-trend
Women Median (μg/day) 5 7 9 11 16
Cases 65 67 71 65 61
Person-time 292,077 253,407 270,527 270,107 260,887
Age-adjusted RR (95% CI) 1.00 (ref) 0.98 ( 0.70, 1.39) 1.00 ( 0.71, 1.40) 0.86 ( 0.61, 1.21) 0.79 ( 0.56, 1.12) 0.43
Multivariable† RR(95% CI) 1.00 (ref) 1.01 ( 0.72, 1.43) 1.03 ( 0.73, 1.45) 0.91 ( 0.65, 1.29) 0.86 ( 0.60, 1.22) 0.66
Men Median (μg/day) 6 8 10 14 22
Cases 14 13 16 13 14
Person-time 104,819 96,427 100,950 96,650 96,991
Age-adjusted RR (95% CI) 1.00 (ref) 1.08 (0.50, 2.33) 1.04 (0.51, 2.16) 0.75 (0.34, 1.68) 0.93 (0.43, 1.97) 0.76
Multivariable RR (95% CI) 1.00 (ref) 1.13 (0.51, 2.52) 1.05 (0.50, 2.24) 0.79 (0.35, 1.80) 0.98 0.44, 2.17) 0.58
Pooled‡ Multivariable RR (95% CI) 1.00 (ref) 1.03 (0.75, 1.42) 1.03 (0.76, 1.41) 0.89 (0.65, 1.23) 0.88 (0.64, 1.21) 0.99
Vitamin B12 from diet * Women Median (μg/day) 4 5 6 7 10
Multivariable RR(95% CI) 1.00 (ref) 0.68 (0.47, 0.99) 0.79 (0.55, 1.13) 1.05 (0.76, 1.46) 1.03 (0.73, 1.43) 0.21
Men Median (μg/day) 5 6 7 9 14
Multivariable RR (95% CI) 1.00 (ref) 1.32 (0.59, 2.96) 1.32 (0.59, 2.96) 0.91 (0.39, 2.14) 1.05 (0.46, 2.40) 0.68
Pooled‡ Multivariable RR (95% CI) 1.00 (ref) 0.86 (0.46, 1.59) 0.89 (0.58, 1.36) 1.03 (0.76, 1.40) 1.03 (0.75, 1.40) 0.41
Vitamin B12 from supplements * Women Median (μg/day) 0 0.2 1 3 7
Multivariable RR(95% CI) 1.00 (ref) 0.76 (0.45, 1.27) 0.78 (0.46, 1.33) 0.81 (0.48, 1.37) 0.52 (0.30, 0.88) 0.05
Men Median (μg/day) 0 0.2 1 4 9
Multivariable RR (95% CI) 1.00 (ref) 1.06 ( 0.40, 2.84) 1.18 (0.43, 3.25) 1.29 (0.49, 3.37) 0.94 (0.34, 2.56) 0.73
Pooled‡ Multivariable RR (95% CI) 1.00 (ref) 0.81 (0.51, 1.29) 0.86 (0.54, 1.37) 0.90 (0.57, 1.43) 0.59 (0.36, 0.98) 0.47
TIMING Baseline∥ Pooled‡ Multivariable RR (95% CI) 1.00 (ref) 1.02 (0.74, 1.40) 1.01 (0.75, 1.35) 1.01 (0.75, 1.36) 0.88 (0.63, 1.23) 0.52
Most recent∥ Pooled‡ Multivariable RR (95% CI) 1.00 (ref) 1.30 (0.94, 1.79) 1.31 (0.95, 1.80) 0.86 (0.61, 1.22) 0.91 (0.64, 1.28) 0.76

Abbreviations: RR = Relative Risk; CI = Confidence Interval

*

Intake calculated using cumulative average (i.e., average of all available intake data from food frequency questionnaires completed before each two-year period at risk).

†

All multivariable analyses were stratified by age in months and period at risk, and they were adjusted for the following variables: ancestry (Scandinavian Caucasian, Southern European Caucasian, All others), family history of glaucoma, self-reported history of high cholesterol, hypertension, diabetes, myocardial infarction, body mass index (22-23, 24-25, 26-27, 28-29, 30+ kg/m2), cumulatively averaged total energy intake (kcal/day), cumulatively averaged alcohol intake (g/day), cumulatively averaged caffeine intake (mg/day), pack-years of smoking (1-9, 10-19, 20-29, 30+ pack-years), lifetime cumulative residential history (northern [41-49° latitude], northern or middle tier [37-49° latitude], middle tier only [37-40° latitude], middle or southern tier [24-40° latitude], southern tier only [24-36° latitude]). For analyses of intake from diet, intake from supplements was adjusted for and vice versa.

‡

Pooled results were calculated using Dersimonian and Laird methods with random effects; p for heterogeneity between cohorts for all results were > 0.05, except for the analysis of most recent intake of vitamin B12 (p-value for heterogeneity=0.03)

∥

Baseline diet refers to diet as of 1980 in the women and 1986 in the men; most recent diet refers to the intake as of the food frequency questionnaire immediately before the 2-year period at risk