Table 1.

Baseline age-adjusted characteristics (means and proportions) by energy-adjusted dietary vitamin B12 quartiles, ATBC Study cohort, 1985-2001 (N = 27,111)

CharacteristicsEnergy-adjusted dietary vitamin B12
Quartile 1 (1.68-8.05)Quartile 2 (8.06-10.11)Quartile 3 (10.12-12.87)Quartile 4 (12.88-62.02)
Dietary vitamin B12 (μg/d)6.569.0611.3716.03
Age (y)57.357.457.057.0
Body mass index (kg/m2)
Height (cm)173.3173.5173.7174.0
Smoking history
    Years smoked36.035.935.936.0
    Elementary school or less (%)83817872
    Up to junior high school (%)12131417
    High school or more (%)56811
Serum HDL (mmol/L)
Dietary intake (per day)*
    Folate (μg)313318328345
    Vitamin B6 (mg)2.262.372.482.67
    Vitamin B2 (mg)2.422.782.943.14
    Methionine (g)1.761.962.072.19
    Alcohol (g)15.617.819.119.4
    Calories (kcal)2,7882,8282,8442,800
    Protein (g)9299103108
        Animal protein (g)58687278
    Fat (g)1011019999
        ω-3 fatty acids from fish0.310.390.480.61
    Vitamin D (μg)
Supplement use (%)
    Vitamin B126.
    Vitamin B611.912.613.114.1
    Vitamin B210.310.711.612.2
Foods (g/d)*
    Red meat55586064
  • NOTE: General linear regression model was used to estimate age-adjusted means of variables for each quartile of energy-adjusted dietary vitamin B12.

    Abbreviation: HDL, high-density lipoprotein cholesterol.

  • * All nutrient and food variables, except alcohol and supplements, were energy adjusted using the residual method (23) to account for their significant correlations with energy.