Table 4.

Association of vitamin B2, B6 (PLP) and B12 baseline plasma levels and the risk of colorectal adenomas by folate treatment group, multivitamin and alcohol use at baseline

Baseline plasma vitamin B levels
PP
Q1
Q2
Q3
Q4
Recurrences/totalRR (95% CI)*Recurrences/totalRR (95% CI)*Recurrences/totalRR (95% CI)*Recurrences/totalRR (95% CI)*
Folic acid treatment group
    Vitamin B2§56/1181.0050/1120.97 (0.72-1.30)51/1120.97 (0.71-1.31)47/1150.85 (0.62-1.18)0.360.66
    Vitamin B657/1151.0049/1120.90 (0.67-1.20)61/1260.99 (0.74-1.33)37/1040.75 (0.53-1.07)0.230.58
    Vitamin B1260/1251.0056/1180.96 (0.72-1.27)46/1090.89 (0.65-1.20)43/1070.86 (0.63-1.19)0.300.58
Placebo group
    Vitamin B2§42/1091.0050/1141.12 (0.81-1.53)46/1121.00 (0.72-1.39)49/1111.10 (0.78-1.55)0.75
    Vitamin B649/1051.0051/1140.95 (0.70-1.28)39/1020.79 (0.57-1.10)48/1250.76 (0.54-1.06)0.07
    Vitamin B1240/971.0050/1031.14 (0.83-1.58)44/1220.88 (0.63-1.23)53/1251.10 (0.79-1.54)0.97
No multivitamin use at baseline**
    Vitamin B2§90/2031.0080/1800.97 (0.77-1.22)72/1480.99 (0.78-1.27)47/1030.93 (0.71-1.24)0.710.43
    Vitamin B697/2051.0095/2030.99 (0.80-1.23)69/1550.93 (0.73-1.19)28/710.84 (0.61-1.17)0.310.89
    Vitamin B1293/2061.0089/1771.05 (0.84-1.32)61/1420.92 (0.72-1.18)47/1110.95 (0.72-1.26)0.520.68
Multivitamin use at baseline**
    Vitamin B2§18/411.0031/681.12 (0.72-1.76)32/960.79 (0.50-1.25)59/1430.94 (0.60-1.45)0.47
    Vitamin B618/391.0018/421.04 (0.63-1.72)42/930.97 (0.63-1.48)62/1740.74 (0.49-1.13)0.08
    Vitamin B1221/401.0030/690.87 (0.57-1.33)37/1060.69 (0.45-1.04)52/1350.77 (0.52-1.15)0.17
No alcohol use at baseline
    Vitamin B2§22/591.0025/720.86 (0.56-1.34)30/770.89 (0.58-1.37)35/880.93 (0.61-1.42)0.860.91
    Vitamin B633/781.0033/711.13 (0.78-1.63)29/740.85 (0.58-1.26)17/730.53 (0.33-0.84)0.010.03
    Vitamin B1222/581.0032/681.17 (0.77-1.76)29/810.87 (0.57-1.34)29/910.83 (0.54-1.29)0.190.50
Alcohol use (≥1 drink/d) at baseline
    Vitamin B2§83/1761.0078/1631.03 (0.81-1.30)73/1590.96 (0.75-1.23)67/1470.96 (0.73-1.26)0.67
    Vitamin B674/1551.0074/1610.96 (0.75-1.23)81/1671.04 (0.81-1.33)72/1620.93 (0.70-1.23)0.86
    Vitamin B1286/1741.0082/1680.95 (0.75-1.21)66/1580.86 (0.67-1.11)68/1470.97 (0.75-1.27)0.63
  • * Adjusted for age, sex, center, duration of follow-up, aspirin treatment group, multivitamin use, and plasma B2, B6, B12, and folate as appropriate.

  • Ptrend.

  • Pinteraction.

  • § Vitamin B2 (riboflavin): Q1, 2.1 to 8.9 nmol/L; Q2, 9.0 to 15.0 nmol/L; Q3, 15.1 to 27.5 nmol/L; and Q4, 27.6 to 479.0 nmol/L.

  • Vitamin B6 (PLP): Q1, 4.7 to 35.6 nmol/L; Q2, 35.7 to 53.3 nmol/L; Q3, 53.4 to 84.3 nmol/L; and Q4, 84.7 to 857.0 nmol/L.

  • Vitamin B12: Q1, 21.4 to 235.9 pmol/L; Q2, 236.4 to 300.3 pmol/L; Q3, 300.5 to 388.8 pmol/L; and Q4, 389.2 to 2,479 pmol/L.

  • ** Adjusted for age, sex, center, duration of follow-up, aspirin treatment group, and plasma B2, B6, B12, and folate as appropriate.