Table 3: Relationship between demographic and disease characteristics of RA patients and vitamin D status.

Vitamin D normalVitamin D insufficiencyVitamin D deficiency

Age (years)57.2 ± 12.7 19–86]56.4 ± 12.8 [18–88]59.2 ± 12.8 [19–88]<0.001
Female sex426 (36.3)640 (54.6)106 (9)0.27
BMI (kg/m)26.9 ± 5.7 15.1–53.9]26.4 ± 5.7 [15.6–50.2]25.9 ± 5.2 [16.1–47.2]0.02
Smoking current/past204 (35.8)152 (26.7)214 (37.5)0.8
High educational level377 (39.7)509 (53.6)64 (6.7)<0.001
Disease duration (years)11.8 ± 10 0.02–56.2]10.1 ± 0.02–56.2]10.3 ± 9.2 0–54]1.0
Glucocorticoid intake249 (36)208 (30.1)234 (33.9)0.04
DAS283.3 ± 0.06 0–8.2]3.5 ± 0.05 0.4–8.1]3.6 ± 0.1 1.1–7.3]0.01
HAQ0.9 ± 0.6 [0.4–3]1.02 ± 0.6 [0.4–3]1.02 ± 0.6 0.4–2.9]0.5

Mean ± DS; number and percentage; vitamin D ≥ 30 ng/mL, 10 ng/mL ≤ vitamin D < 30 ng/mL, and vitamin D < 10 ng/mL; BMI: body mass index; DAS28: Disease Activity Score using 28 joints; HAQ: health assessment questionnaire; significant if ≤0.05.