Table 3.
Multivariate analysis of relative risk for vitamin D deficiency [25(OH)D < 20 ng/mL].
| Total | % of subjects | Odds ratio | 95% CI | P-value | |
|---|---|---|---|---|---|
| (N = 1,684) | with 25(OH)D < 20 ng/mL | (Adjusted) | |||
| AGE | |||||
| ≤70/>70 | 1,211/473 | 61.3/61.5 | Ref/1.36 | (0.89–2.10) | 0.16 |
| RESIDENTIAL REGION | |||||
| Urban/Rural | 844/840 | 64.9/57.7 | Ref/0.59 | (0.40–0.86) | < 0.01 |
| EDUCATION | |||||
| No education | 317 | 65 | Ref | – | |
| Primary/Elementary school | 642 | 58.9 | 0.62 | (0.42–0.93) | 0.02 |
| College/University/Graduate school | 129 | 60.5 | 0.51 | (0.25–1.02) | 0.06 |
| BMI | |||||
| < 24 kg/m2/≥24 kg/m2 | 702/982 | 58.0/63.7 | Ref/1.11 | (0.78–1.58) | 0.57 |
| SEASON* | |||||
| Summer/Winter | 722/721 | 41.3/84.7 | Ref/7.62 | (5.52–10.54) | < 0.0001 |
| FRAGILITY FRACTURE AFTER 45 | |||||
| Yes/No | 261/1,423 | 61.7/61.3 | Ref/0.83 | (0.56–1.23) | 0.35 |
| GENERAL HEALTH | |||||
| Excellent-Very Good/Fair-Poor | 261/937 | 62.5/59.6 | Ref/0.57 | (0.38–0.86) | < 0.01 |
| READ OR TOLD ABOUT VITAMIN D AND BONE HEALTH | |||||
| Yes/No | 609/939 | 59.8/61.9 | Ref/0.93 | (0.65–1.32) | 0.67 |
| FALL FROM STANDING HEIGHT | |||||
| Yes/No | 57/1,624 | 57.9/61.4 | Ref/0.99 | (0.46–2.15) | 0.98 |
| PARENTAL HISTORY OF HIP FRACTURE | |||||
| Yes/No | 107/1,509 | 69.2/60.9 | Ref/0.43 | (0.23–0.81) | < 0.01 |
| ENGAGE IN STRENUOUS EXERCISE OR FARM WORKS | |||||
| Yes/No | 367/1,317 | 53.7/63.5 | Ref/1.15 | (0.82–1.62) | 0.41 |
| TEA DRINK | |||||
| Yes/No | 615/1,069 | 61.3/61.4 | Ref/0.83 | (0.62–1.11) | 0.21 |
| MILK PRODUCT WITH VIT D | |||||
| Yes/No any milk product | 56/919 | 48.2/61.7 | Ref/1.41 | (0.66–3.00) | 0.38 |
| FISH CONSUMPTION** | |||||
| Yes/No | 708/976 | 65.8/58.1 | Ref/0.86 | (0.63–1.16) | 0.32 |
| EGG WITH YOLK | |||||
| Yes/No | 1,256/428 | 58.9/68.5 | Ref/1.60 | (1.15–2.22) | < 0.01 |
| OSTA SCORE | |||||
| Low (>-1) | 759 | 63.1 | Ref | – | |
| Medium (−1 to −4) | 649 | 60.2 | 0.91 | (0.63–1.32) | 0.63 |
| High (< -4) | 276 | 59.1 | 0.82 | (0.44–1.50) | 0.51 |
| VITAMIN D SUPPLEMENT USE ++ | |||||
| Yes/No | 150/1,534 | 50.7/62.4 | Ref/1.75 | (1.08–2.85) | 0.02 |
| SUN EXPOSURE INDEX*** | |||||
| High | 520 | 51.5 | Ref | – | |
| Middle | 457 | 66.7 | 1.31 | (0.94–1.85) | 0.12 |
| Low | 450 | 70.4 | 1.12 | (0.79–1.60) | 0.53 |
Subjects with “Unknown” in any category were excluded from analysis;
**
Reported consumption of fish at least once in the past month;
++Excluded subjects using active analogs (alfacalcidol and calcitriol).
***
Calculated as the number of hours per week spent outside without sun protection multiplied by percentage body part exposed to sunlight (9% for face, 1% for each hand, 9% for each arm, and 18% for each leg). Sun exposure index was categorized into tertiles.