Table 1.
Demographic and biochemical characteristics according to dietary vitamin C (VC) intake status and their association with the VC status.
| Low Intake of VC (n = 36,198) | High Intake of VC (n = 27,509) |
Adjusted OR 1 or Beta Coefficients 2 and 95% CI | |
|---|---|---|---|
| Age (year) | 54.6 ± 8.50 3 | 53.4 ± 8.00 *** | −0.684 (−0.749–−0.618) ### |
| Gender (male, %) | 14,183 (39.2) 4 | 9187(33.4) *** | 0.563 (0.531–0.597) ### |
| BMI (mg/kg2) | 24.0 ± 2.94 | 24.1 ± 2.91 *** | 0.485 (0.298–0.672) ### |
| Waist circumferences (cm) | 81.5 ± 8.73 | 81.3 ± 8.71 ** | −0.111 (-0.174–−0.049) ### |
| Education (Yes, %) | |||
| ≤Middle school High school ≥Collage |
15,752 (43.8) 13,227 (36.8) 6954 (19.4) |
9661(35.4) *** 11,042 (40.5) 6564 (24.1) |
1 1.234 (1.180–1.291) ### 1.466 (1.386–1.550) ### |
| Income (Yes, %) | |||
| ≤$2000 $2000–4000 >$4000 |
12,647 (39.3) 17,436 (54.2) 2069 (6.5) |
8142 (32.6) *** 14,728 (59.0) 2087 (8.4) |
1 1.136 (1.085–1.189) ### 1.413 (1.287–1.551) ### |
| Smoke (Yes, %) | 11,092 (30.7) | 7029 (25.6) *** | 0.879 (0.828–0.934) ### |
| Alcohol intake (g/day) | 4.28 ± 14.3 | 3.98 ± 12.2 ** | −0.021 (-0.061–0.019) |
| Physical activity (Yes, %) | 17,348 (48.0) | 15,322 (55.8) *** | 1.307 (1.260–1.355) ### |
| Metabolic syndrome (Yes, %) | 9855 (27.4) | 6960(25.4) *** | 0.905(0.873–0.937) ### |
| Serum glucose (mg/dL) | 95.7 ± 20.9 | 94.3 ± 19.2 *** | −0.146 (−0.173–−0.118) ### |
| HbA1c (%) | 5.73 ± 0.75 | 5.72 ± 0.76 | −1.014 (−2.062–0.035) |
| Blood hemoglobin (g/dL) | 13.7 ± 0.01 | 13.9 ± 0.01 ** | 0.00834 (0.00811–0.00847) ## |
| Hematocrit (%) | 41.6 ± 0.02 | 41.8 ± 0.02 ** | 0.00423 (0.00394–0.00465) # |
| Serum total cholesterol (mg/dL) | 197 ± 35.8 | 197 ± 35.5 | −0.003 (−0.019–0.012) |
| Serum HDL (mg/dL) | 51.8 ± 13.1 | 52.3 ± 12.9 *** | 0.076 (0.034–0.118) ### |
| Serum LDL (mg/dL) | 119 ± 33.0 | 119 ± 32.8 ** | 0.010 (−0.006–0.027) |
| Serum TG (mg/dL) | 132 ± 90.8 | 128 ± 87.5 *** | −0.017 (−0.023–−0.011) ### |
| SBP (mmHg) | 123 ± 15.5 | 122 ± 15.3 *** | −0.166 (−0.201–−0.130) ### −0.048 (−0.102–0.006) |
| DBP (mmHg) | 76.6 ± 10.1 | 76.4 ± 10.1 | |
| Serum C-reactive protein (mg/L) | 0.37 ± 1.57 | 0.30 ± 1.65 *** | −0.981 (−1.355–−0.607) ### |
| eGFR (mL/min) | 83.8 ± 16.4 | 84.4 ± 16.2 *** | 0.127 (0.094–0.161) ### |
| Serum AST (U/L) | 24.5 ± 27.4 | 24.1 ± 16.0 | −0.012 (−0.036–0.011) 0.002 (−0.022–0.026) |
| Serum ALT(U/L) | 23.0 ± 25.9 | 22.9 ± 18.3 |
1 Adjusted odds ratio (OR) and 95% confidence intervals (CI) represent the association of each categorical variable with dietary VC intake in logistic regression. 2 Adjusted beta-coefficient and 95% CI represent the relationship of each continuous variable with dietary VC intake in linear regression. 3 Adjusted means ± standard deviations. 4 Number of the subjects (percentage of each group). Covariates included age, gender, residence areas, BMI, education, income, daily activity, alcohol intake, and smoking status. ** Significant differences from the low VC intake group at p < 0.01 and *** at p < 0.001. # Significant association of the low VC intake group with the designated variable at p < 0.05, ## p < 0.01 and ### at p < 0.001.