Supplementary Table 1. Baseline Characteristics of the Study Population by Quartile of Riboflavin Intake1

Riboflavin intake / Quartile1 / Quartile 2 / Quartile 3 / Quartile 4
Number of participants / 17,818 / 17,819 / 17,816 / 17,814
Age at baseline (years) / 55.1 ± 9.63 / 52.5 ± 8.99 / 51.5 ± 8.56 / 50.4 ± 8.00
Education
Elementary school or less / 27.4% / 21.0% / 16.4% / 12.7%
Middle school / 42.5% / 39.6% / 36.5% / 34.0%
High school / 22.2% / 27.7% / 30.7% / 33.2%
Professional education/college or more / 7.9% / 11.7% / 16.4% / 20.2%
Income
<10,000 yuan / 19.3% / 16.2% / 13.7% / 13.7%
10,000-20,000 yuan / 41.8% / 39.0% / 38.0% / 35.4%
20,000-30,000 yuan / 25.8% / 28.2% / 29.0% / 29.0%
≥30,000 yuan / 13.2% / 16.7% / 19.2% / 21.4%
Occupation
Housewife / 0.5% / 0.3% / 0.2% / 0.2%
Professional workers / 20.9% / 27.1% / 32.7% / 37.0%
Clerical workers / 21.6% / 20.7% / 20.6% / 20.0%
Manual laborers / 57.0% / 51.8% / 46.6% / 42.9%
Family history of any cancer / 24.7% / 26.6% / 27.8% / 27.7%
Family history of lung cancer / 4.5% / 4.9% / 5.2% / 5.1%
Personal history of lung disease
Tuberculosis / 4.9% / 5.2% / 6.0% / 6.4%
Chronic bronchitis / 6.4% / 7.2% / 7.5% / 8.4%
Asthma / 2.1% / 2.0% / 2.1% / 2.4%
BMI (kg/m2) / 24.1 ± 0.03 / 24.1 ± 0.02 / 23.9 ± 0.02 / 23.9 ± 0.02
Waist-to-hip ratio / 0.814 ± 0.0004 / 0.812 ± 0.0004 / 0.809 ± 0.0004 / 0.807 ± 0.0004
Passive smoking
None / 18.1% / 19.0% / 19.9% / 22.0%
At household or workplace / 55.3% / 52.7% / 51.4% / 49.6%
Both / 26.6% / 28.3% / 28.7% / 28.4%
Ever consumed alcohol / 1.5% / 1.8% / 1.9% / 2.4%
Ever consumed tea / 23.0% / 27.5% / 31.8% / 35.6%
Postmenopausal / 48.2% / 48.3% / 48.1% / 48.3%
Vitamin supplement use
B vitamin-containing / 5.8% / 8.9% / 12.3% / 15.4%
Any vitamin / 12.0% / 17.3% / 22.7% / 27.5%
Regular exercise2 / 27.3% / 33.1% / 37.5% / 42.2%

1Adjusted for age at baseline and presented as mean ± standard error or frequency (%), except for age at baseline where unadjusted mean ± standard deviation is shown.

2Defined as at least once per week continuously for at least three months within the past five years.

Supplementary Table 2. Risk of Lung Cancer by Intakes of Food Groups (g/day)1

Food groups2 / Quartiles / Median / Cases / HR / 95% CI / P-trend
All vegetables / 1 / 136 / 132 / Reference
2 / 220 / 99 / 0.86 / 0.66, / 1.11
3 / 310 / 94 / 0.83 / 0.63, / 1.09
4 / 475 / 103 / 0.93 / 0.70, / 1.23 / 0.69
Allium / 1 / 2 / 116 / Reference
vegetables / 2 / 4 / 122 / 1.15 / 0.89, / 1.49
3 / 7 / 93 / 0.94 / 0.72, / 1.25
4 / 16 / 97 / 1.00 / 0.75, / 1.32 / 0.65
Cruciferous / 1 / 32 / 118 / Reference
vegetables / 2 / 65 / 106 / 0.90 / 0.69, / 1.17
3 / 98 / 102 / 0.94 / 0.72, / 1.22
4 / 158 / 102 / 0.84 / 0.64, / 1.11 / 0.28
Green leafy / 1 / 2 / 118 / Reference
vegetables / 2 / 6 / 113 / 1.08 / 0.83, / 1.39
3 / 10 / 92 / 0.93 / 0.70, / 1.22
4 / 23 / 105 / 1.00 / 0.76, / 1.31 / 0.85
Legumes / 1 / 9 / 110 / Reference
2 / 19 / 113 / 1.10 / 0.85, / 1.43
3 / 31 / 99 / 0.95 / 0.72, / 1.25
4 / 56 / 106 / 0.98 / 0.74, / 1.30 / 0.65
Eggs / 1 / 6 / 168 / Reference
2 / 19 / 109 / 0.92 / 0.72, / 1.17
3 / 44 / 134 / 0.85 / 0.67, / 1.08
4 / 87 / 17 / 0.87 / 0.52, / 1.44 / 0.26
Fish / 1 / 13 / 123 / Reference
2 / 30 / 121 / 1.23 / 0.96, / 1.59
3 / 51 / 100 / 1.11 / 0.84, / 1.46
4 / 96 / 84 / 1.02 / 0.76, / 1.38 / 0.79
Poultry / 1 / 2 / 133 / Reference
2 / 7 / 115 / 1.06 / 0.83, / 1.37
3 / 14 / 96 / 0.94 / 0.72, / 1.23
4 / 29 / 84 / 0.90 / 0.67, / 1.21 / 0.34
Red meat / 1 / 17 / 137 / Reference
2 / 35 / 99 / 0.83 / 0.64, / 1.08
3 / 53 / 106 / 0.97 / 0.75, / 1.27
4 / 87 / 86 / 0.85 / 0.63, / 1.16 / 0.47
Rice / 1 / 229 / 108 / Reference
2 / 286 / 99 / 0.96 / 0.72, / 1.27
3 / 329 / 104 / 0.98 / 0.73, / 1.33
4 / 410 / 117 / 1.10 / 0.76, / 1.60 / 0.58
Dairy foods / None / - / 229 / Reference
Any / - / 199 / 0.79 / 0.65, / 0.96 / 0.02
All fruits / 1 / 78 / 121 / Reference
2 / 189 / 112 / 1.13 / 0.87, / 1.47
3 / 295 / 105 / 1.15 / 0.88, / 1.51
4 / 460 / 90 / 1.11 / 0.83, / 1.48 / 0.50

1Adjusted for age (continuous), passive smoking (none, at household or workplace, or both locations), total caloric intake (continuous), income (four categories ranging from <10,000 yuan to ≥30,000 yuan), occupation (housewife/clerical workers, professional workers, or manual laborers), BMI category (five categories ranging from BMI < 23 to BMI ≥27.5 kg/m2), and history of asthma (yes or no).

2The statistically significant inverse association between soy food intake and lung cancer risk in the same study population was reported in another publication[25].

Supplementary Figure 1. Forest Plots forthe Meta-analysis of the Association between Riboflavin and Lung Cancer Risk in Previous Studies1

1OR: odds ratio; RR: relative risk; HR, hazard ratio

Supplementary Figure 2. Forest Plots for the Meta-analysis of Associations between Folate and Lung Cancer Risk in Previous Studies1

A. All studies withself-reported intake

B. Case-control studies withself-reported intake

C. Cohort studies with self-reported intake

D. Never Smokers

1OR: odds ratio; RR: relative risk; HR, hazard ratio

1