Table 3.

Relative risks (95% CI) for colorectal, colon, and rectal cancer by quintiles of indices for vitamins B2, B6, and B12 status

SiteMatched analysesMatched + covariate adjusted analyses
Cases/ControlsRR/quintilePtrend*Cases/ControlsRR/quintilePtrendQ1Q2Q3Q4Q5
Colorectal cancer
Vitamin B2 sum1,336/2,2540.94 (0.89-0.99)0.021,296/2,1750.94 (0.88-0.99)0.0210.73 (0.58-0.92)0.83 (0.65-1.05)0.73 (0.57-0.93)0.71 (0.56-0.91)
    Riboflavin1,358/2,3150.97 (0.92-1.02)0.211,318/2,2360.97 (0.92-1.02)0.2710.88 (0.70-1.10)0.84 (0.66-1.07)0.84 (0.66-1.07)0.87 (0.68-1.11)
    FMN1,337/2,2540.89 (0.85-0.95)<0.0011,297/2,1750.89 (0.84-0.94)<0.00110.77 (0.61-0.97)0.81 (0.64-1.02)0.54 (0.42-0.69)0.65 (0.50-0.83)
Vitamin B6 sum1,338/2,2760.94 (0.89-0.99)0.011,298/2,1970.93 (0.88-0.98)0.0210.91 (0.72-1.13)0.83 (0.66-1.05)0.92 (0.73-1.17)0.68 (0.53-0.87)
    PLP1,359/2,3160.90 (0.85-0.95)<0.0011,319/2,2370.89 (0.84-0.94)<0.00110.80 (0.64-1.00)0.73 (0.58-0.91)0.73 (0.57-0.92)0.59 (0.47-0.76)
    PL1,355/2,3020.95 (0.90-1.00)0.061,315/2,2230.90 (0.85-0.95)0.0310.79 (0.63-0.99)0.73 (0.57-0.93)0.84 (0.66-1.07)0.70 (0.54-0.90)
    PA1,346/2,2881.00 (0.95-1.06)0.901,306/2,2090.94 (0.89-0.99)0.8311.04 (0.82-1.31)1.24 (0.98-1.56)1.07 (0.84-1.37)1.01 (0.78-1.30)
Cobalamin1,362/2,3031.02 (0.96-1.07)0.581,322/2,2251.03 (0.97-1.08)0.1910.86 (0.69-1.08)1.02 (0.81-1.28)1.08 (0.85-1.35)1.02 (0.80-1.29)
MMA1,365/2,3130.99 (0.94-1.04)0.721,325/2,2341.02 (0.96-1.08)0.9711.09 (0.87-1.36)1.16 (0.92-1.46)1.18 (0.94-1.49)0.94 (0.74-1.21)
Colon
Vitamin B2 sum630/1,4360.91 (0.85-0.97)<0.005805/1,3920.91 (0.85-0.97)0.0110.74 (0.56-1.00)0.72 (0.54-0.97)0.66 (0.49-0.89)0.66 (0.48-0.90)
    Riboflavin842/1,4670.95 (0.89-1.02)0.15817/1,4230.96 (0.89-1.02)0.1910.88 (0.66-1.16)0.81 (0.60-1.09)0.74 (0.55-1.00)0.86 (0.63-1.15)
    FMN831/1,4360.86 (0.80-0.92)<0.001806/1,3920.87 (0.81-0.93)<0.00110.76 (0.58-1.01)0.76 (0.57-1.01)0.53 (0.39-0.73)0.59 (0.43-0.81)
Vitamin B6 sum829/1,4460.93 (0.87-1.00)0.05804/1,4020.93 (0.86-1.00)0.0110.93 (0.70-1.23)0.75 (0.56-1.01)0.89 (0.67-1.20)0.69 (0.50-0.96)
    PLP843/1,4680.90 (0.85-0.97)<0.005818/1,4240.90 (0.84-0.97)<0.00510.79 (0.60-1.04)0.62 (0.47-0.83)0.74 (0.55-0.99)0.63 (0.46-0.86)
    PL839/1,4600.95 (0.88-1.02)0.13814/1,4160.94 (0.87-1.01)0.0810.73 (0.54-0.97)0.67 (0.49-0.91)0.80 (0.59-1.08)0.68 (0.49-0.94)
    PA834/1,4541.02 (0.95-1.09)0.58809/1,4101.02 (0.95-1.09)0.6311.11 (0.83-1.50)1.28 (0.96-1.72)1.13 (0.83-1.54)1.07 (0.78-1.48)
Cobalamin844/1,4611.00 (0.94-1.07)0.97819/1,,4181.01 (0.94-1.08)0.0510.76 (0.57-1.01)1.03 (0.77-1.36)0.90 (0.67-1.22)0.95 (0.70-1.28)
MMA846/1,4670.97 (0.90-1.04)0.34821/1,4230.99 (0.92-1.06)0.6711.32 (0.99-1.76)1.08 (0.81-1.46)1.24 (0.93-1.67)0.95 (0.69-1.30)
Rectal
Vitamin B2 sum506/8181.00 (0.92-1.09)0.96491/7830.99 (0.90-1.09)0.8110.73 (0.48-1.09)1.14 (0.75-1.73)0.94 (0.61-1.43)0.84 (0.55-1.28)
    Riboflavin516/8481.00 (0.91-1.09)0.95501/8131.00 (0.91-1.10)0.9310.88 (0.59-1.32)0.95 (0.63-1.45)1.06 (0.69-1.62)0.92 (0.60-1.40)
    FMN506/8180.95 (0.87-1.04)0.27491/7830.91 (0.83-1.01)0.0610.80 (0.53-1.20)0.91 (0.60-1.37)0.55 (0.36-0.85)0.74 (0.48-1.15)
Vitamin B6 sum509/8300.95 (0.87-1.03)0.19494/7950.94 (0.86-1.03)0.2010.85 (0.57-1.25)1.06 (0.71-1.57)1.01 (0.67-1.51)0.69 (0.46-1.04)
    PLP516/8480.90 (0.83-0.98)0.01501/8130.89 (0.81-0.97)0.0110.84 (0.57-1.23)1.01 (0.68-1.49)0.74 (0.49-1.11)0.58 (0.39-0.87)
    PL516/8420.96 (0.88-1.04)0.31501/8070.95 (0.87-1.04)0.2810.93 (0.63-1.37)0.86 (0.58-1.27)0.96 (0.64-1.45)0.77 (0.51-1.17)
    PA512/8340.98 (0.90-1.08)0.72497/7991.00 (0.91-1.10)0.9810.93 (0.63-1.38)1.20 (0.82-1.76)1.02 (0.68-1.53)0.95 (0.63-1.45)
Cobalamin518/8421.04 (0.96-1.13)0.31503/8071.06 (0.97-1.15)0.2311.15 (0.78-1.70)1.00 (0.68-1.46)1.42 (0.97-2.07)1.17 (0.80-1.73)
MMA519/8461.03 (0.95-1.12)0.50504/8111.03 (0.94-1.12)0.5410.82 (0.56-1.20)1.33 (0.91-1.93)1.15 (0.79-1.69)0.96 (0.64-1.43)

NOTE: Counts do not necessarily add to the total sum due to missing data.

The lower quintile is the reference category. All analyses are matched for age, sex, study center, and date of blood collection. The matched + covariate adjusted analyses are further adjusted for smoking status, education level, physical activity, fiber intake, intake of red and processed meat, alcohol consumption, and body mass index (BMI).

The cutoff values for the quintiles of the vitamin B2 sum were 14.2, 18.1, 23.5, and 33.4 μmol/L; for riboflavin they were 9.4, 12.8, 17.2, and 25.4 μmol/L; for FMN they were 3.3, 4.6, 6.3, and 8.8 μmol/L; for the vitamin B6 sum they were 45.4, 57.7, 72.6, and 105.3 μmol/L; for PLP they were 21.7, 29.1, 38.4, and 56.6 μmol/L; for PL they were 9.4, 11.8, 15.0, and 20.6 μmol/L; for PA they were 11.1, 14.6, 19.2, and 29.0 μmol/L; for vitamin B12 they were 220, 266, 312, and 380 pmol/L; and for MMA they were 0.14, 0.16, 0.18, and 0.22 μmol/L.

  • *Ptrend (two-sided) in risk calculated with conditional logistic regression models without any covariates in the model using values for quintile categories as the quantitative score of exposure.

  • Ptrend (two-sided) in risk calculated with conditional logistic regression models with the covariates in the model using values for quintile categories as the quantitative score of exposure.