TABLE 2.
Factors associated with vitamin B-6 and riboflavin status in Irish adults1
| Total cohort (n = 765) | |||
|---|---|---|---|
| β (95% CI) | β | P | |
| Plasma PLP | |||
| B-vitamin supplement use2 | 81.72 (66.01, 97.43) | 0.35 | <0.001 |
| Dietary vitamin B-6 intake, mg/d | 2.49 (1.75, 3.24) | 0.22 | <0.001 |
| Fortified food consumption | 12.49 (2.08, 22.91) | 0.07 | 0.019 |
| Energy, MJ/d | −1.18 (−3.40, 1.05) | −0.04 | 0.299 |
| Age, y | −0.13 (−0.50, 0.23) | −0.03 | 0.469 |
| Female sex | −0.99 (−24.70, 22.73) | −0.01 | 0.935 |
| BMI, kg/m2 | −1.81 (−3.31, −0.30) | −0.10 | 0.019 |
| Alcohol, units/wk | 0.02 (−0.05, 0.09) | 0.02 | 0.621 |
| Current smoker | −5.22 (−18.57, 8.13) | −0.02 | 0.443 |
| Serum creatinine, µmol/L | 0.06 (−0.38, 0.50) | 0.01 | 0.786 |
| Serum hsCRP, µmol/L | −1.68 (−3.55, 0.20) | −0.06 | 0.080 |
| Hemoglobin, g/dL | 0.98 (−3.76, 5.72) | 0.02 | 0.686 |
| Muscle mass, kg | 0.83 (−0.28, 1.95) | 0.11 | 0.142 |
| EGRac | −65.81 (−99.08, −32.54) | −0.13 | <0.001 |
| Adjusted R² | 0.30 | ||
| EGRac | |||
| B-vitamin supplement use2 | −0.07 (−0.11, −0.04) | −0.16 | <0.001 |
| Dietary riboflavin intake, mg/d | ←0.01 (←0.01, <0.01) | −0.09 | 0.016 |
| Fortified food consumption | −0.04 (−0.07, −0.02) | −0.12 | 0.001 |
| Milk consumption | −0.04 (−0.07, −0.01) | −0.11 | 0.003 |
| Age, y | ←0.01 (←0.01, ←0.01) | −0.15 | <0.001 |
| Female sex | −0.01 (−0.06, 0.04) | −0.02 | 0.818 |
| BMI, kg/m2 | <0.01 (←0.01, <0.01) | 0.01 | 0.795 |
| Alcohol, units/week | <0.01 (←0.01, <0.01) | 0.05 | 0.129 |
| Current smoker | 0.06 (0.03, 0.09) | 0.14 | <0.001 |
| Serum creatinine, µmol/L | ←0.01 (←0.01, <0.01) | −0.05 | 0.276 |
| Serum hsCRP, µmol/L | <0.01 (←0.01, 0.01) | 0.02 | 0.539 |
| Hemoglobin, g/dl | −0.02 (−0.03, −0.01) | −0.14 | 0.001 |
| Muscle mass, kg | <0.01 (←0.01, <0.01) | 0.01 | 0.875 |
| Adjusted R² | 0.14 | ||
Values are nonstandardized regression coefficients (β), corresponding 95% CIs, and standardized coefficients (β). Multiple linear regression analyses were performed using plasma PLP concentration and EGRac as dependent variables, respectively, using data from the National Adult Nutrition Survey (NANS) of Irish adults. In the plasma PLP model, B-vitamin supplement use (nonconsumers of B-vitamin supplements as reference category), dietary vitamin B-6 intake (mg/d), fortified food consumer (nonconsumers and lowest tertile of vitamin B-6 intake from fortified foods as reference category), age (y), sex (male as reference category), BMI (kg/m²), alcohol intake (units/wk), smoking (nonsmoker as reference category), serum creatinine (µmol/L), hsCRP (µmol/L), hemoglobin (g/dL, muscle mass (kg), and EGRac were included in the model as independent variables. In the riboflavin model, B-vitamin supplement use (nonconsumers of B-vitamin supplements as reference category), dietary riboflavin intake (mg/d), fortified food consumer (nonconsumers and lowest tertile of riboflavin intake from fortified foods as reference category), milk consumption (lowest quartile of milk intake as reference category) age (y), sex (male as reference category), BMI (kg/m²), alcohol intake (units/wk), smoking (nonsmoker as reference category), serum creatinine (µmol/L), hsCRP (µmol/L), hemoglobin (g/dL), and muscle mass (kg) were included in the model as independent variables. Higher EGRac values are indicative of lower status. EGRac, erythrocyte glutathione reductase activation coefficient; hsCRP, high-sensitivity C-reactive protein; PLP, pyridoxal 5´-phosphate.
Supplement users identified as those consuming supplemental B-vitamins (in tablet form) during food diary recording.