Table 1. Baseline sample characteristics according to quartiles of riboflavin intake (n = 1253). a .
| Q1 | Q2 | Q3 | Q4 | pb | |
| (n = 313) | (n = 313) | (n = 313) | (n = 314) | ||
| Age | 51.3(14.0) | 49.9(13.0) | 48.9(12.7) | 47.4(12.6) | 0.002 |
| BMI (kg/m2) | 23.3(3.7) | 23.5(3.5) | 23.6(3.4) | 23.3(2.9) | 0.671 |
| Overweight/obesity (%) (BMI≥24 kg/m2) | 38.2 | 40.3 | 44.4 | 37.8 | 0.314 |
| Hemoglobin (g/dL) | 13.0(1.7) | 13.0(1.7) | 13.3(1.7) | 13.5(1.9) | <0.001 |
| Ferritin (µg/l) | 81.1(66) | 93.4(78.7) | 104.3(81.8) | 111.1(89.7) | <0.001 |
| Ferritin <15 µg/l (%) | 10.0 | 8.7 | 8.4 | 6.8 | 0.001 |
| Nutrient intake | |||||
| Energy (kcal) | 1841.9(460.4) | 2210.5(458.6) | 2512.8(575.2) | 2766.2(677.7) | <0.001 |
| Fat (g/d) | 59.8(24.5) | 74.4(28.2) | 90.3(35.2) | 101.7(39.6) | <0.001 |
| Protein (g/d) | 53(12.2) | 66.5(12.7) | 78.1(15.4) | 92.1(23.3) | <0.001 |
| Total iron (mg/d) | 19.3(7.6) | 21.9(6.2) | 25.9(7.3) | 32.5(11.1) | <0.001 |
| Non-heme iron (mg/d) | 18.2(7.9) | 20.1(6.5) | 23.3(7.4) | 27.8(11.5) | <0.001 |
| Heme iron (mg/d) | 1.1(1.2) | 1.8(1.9) | 2.6(3) | 4.7(5.7) | <0.001 |
| Vitamin C (mg/d) | 45.3(22.9) | 63.4(33.3) | 66.5(33.5) | 84.8(45.5) | <0.001 |
| Riboflavin (mg/d) | 0.5(0.1) | 0.7(0) | 0.8(0.1) | 1.3(0.3) | <0.001 |
| Fiber (g/d) | 10.3(9.6) | 10.5(7.9) | 11.2(6.5) | 14.4(12.1) | <0.001 |
| Alcohol intake (g/d) | 0.7(3.7) | 1.4(4.9) | 2(5.6) | 3.1(6.1) | <0.001 |
| Women (%) | 77.7 | 63.9 | 49.5 | 42.8 | <0.001 |
| Anemia (baseline) (%) | 30.9 | 32.6 | 31.0 | 28.4 | 0.730 |
| Hypertension (%) | 31.8 | 28.1 | 33.5 | 29.7 | 0.475 |
| Smoker (%) | 16.9 | 21.4 | 30.4 | 39.6 | <0.001 |
| Alcohol drinker (%) | 12.4 | 18.2 | 30.0 | 38.3 | <0.001 |
| Education | |||||
| Low (%) | 64.3 | 57.5 | 53.7 | 39.6 | |
| Medium (%) | 28.0 | 32.6 | 35.8 | 44.7 | <0.001 |
| High (%) | 7.6 | 9.9 | 10.5 | 15.7 | |
| Manual job (%) | 51.6 | 48.6 | 53 | 50.2 | 0.710 |
| Income | |||||
| Low (%) | 34.7 | 27.3 | 19.6 | 18.8 | |
| Medium (%) | 33.4 | 38.6 | 36.9 | 25.2 | <0.001 |
| High (%) | 31.8 | 34.1 | 43.6 | 56.0 |
a
Values are presented as mean(SD) or percentage.
b
p values were generated by chi-squared test for categorical variables and ANOVA test for continuous exposures.