Table 3.
Subgroup analysis for associations between serum 25(OH)D and the risk of anemia.
| Serum 25(OH)D | Q1 OR (95% CI) |
Q2 OR (95% CI) |
Q3 OR (95% CI) |
Q4 OR (95% CI) |
P for trend | P for interaction |
|---|---|---|---|---|---|---|
| Age | ||||||
| <60 | 1.00 | 0.689 (0.589, 0.806) ∗∗∗ | 0.470 (0.390, 0.565) ∗∗∗ | 0.476 (0.388, 0.583) ∗∗∗ | <0.001 | <0.001 |
| ≥60 | 1.00 | 0.884 (0.726, 1.076) | 0.682 (0.557, 0.836) ∗∗∗ | 1.073 (0.892, 1.292) | <0.001 | |
|
| ||||||
| Gender | ||||||
| Male | 1.00 | 0.759 (0.612, 0.940) ∗ | 0.508 (0.404, 0.639) ∗∗∗ | 0.866 (0.697, 1.075) | <0.001 | <0.001 |
| Female | 1.00 | 0.734 (0.631, 0.853) ∗∗∗ | 0.558 (0.471, 0.662) ∗∗∗ | 0.620 (0.524, 0.734) ∗∗∗ | <0.001 | |
|
| ||||||
| Race | ||||||
| Mexican American | 1.00 | 0.905 (0.663, 1.236) | 0.764 (0.527, 1.106) | 1.117 (0.724, 1.723) | 0.378 | <0.001 |
| Other Hispanic | 1.00 | 0.783 (0.488, 1.256) | 0.711 (0.428, 1.183) | 0.874 (0.499, 1.532) | 0.573 | |
| Non-Hispanic Black | 1.00 | 0.989 (0.817, 1.196) | 0.742 (0.581, 0.948) ∗ | 1.022 (0.802, 1.303) | 0.092 | |
| Non-Hispanic White | 1.00 | 1.031 (0.774, 1.373) | 0.982 (0.744, 1.296) | 1.308 (1.005, 1.703) ∗ | 0.019 | |
| Other race | 1.00 | 1.195 (0.783, 1.824) | 0.421 (0.243, 0.730) ∗∗ | 0.755 (0.463, 1.232) | 0.002 | |
|
| ||||||
| Hypertension | ||||||
| No | 1.00 | 0.675 (0.567, 0.804) ∗∗∗ | 0.471 (0.386, 0.574) ∗∗∗ | 0.505 (0.409, 0.625) ∗∗∗ | <0.001 | 0.001 |
| Yes | 1.00 | 0.791 (0.668, 0.937) ∗∗ | 0.579 (0.482, 0.695) ∗∗∗ | 0.864 (0.730, 1.022) | <0.001 | |
|
| ||||||
| DM | ||||||
| No | 1.00 | 0.680 (0.590, 0.783) ∗∗∗ | 0.467 (0.398, 0.547) ∗∗∗ | 0.624 (0.535, 0.729) ∗∗∗ | <0.001 | <0.001 |
| Yes | 1.00 | 0.921 (0.728, 1.164) | 0.728 (0.566, 0.936) ∗ | 0.934 (0.733, 1.191) | 0.088 | |
|
| ||||||
| Obesity | ||||||
| <30 kg/m2 | 1.00 | 0.761 (0.647, 0.895) ∗∗ | 0.538 (0.453, 0.639) ∗∗∗ | 0.619 (0.523, 0.732) ∗∗∗ | <0.001 | <0.001 |
| ≥30 kg/m2 | 1.00 | 0.718 (0.597, 0.862) ∗∗∗ | 0.504 (0.405, 0.627) ∗∗∗ | 0.863 (0.701, 1.062) | <0.001 | |
Q1, 6.31–44.4 nmol/L; Q2, 44.5–60.6 nmol/L; Q3, 60.7–77.7 nmol/L; Q4, 77.8–422 nmol/L; Serum 25(OH)D, serum 25-hydroxyvitamin D; ∗, P < 0.05; ∗∗, P < 0.01; ∗∗∗, P < 0.001; OR, odd ratio; CI, confidence interval. Analysis was adjusted for age, gender, race/ethnicity, education level, marital status, family poverty income ratio, hypertension, diabetes mellitus, smoke status, and drink status, the history of coronary heart disease, congestive heart failure, angina pectoris, heart attack, stroke, and chronic kidney diseases, body mass index, waist circumference, folic acid intake, Vitamin B12 intake, Vitamin C intake, iron intake, serum iron, calcium, and phosphorus.