Table 2.
Impact of vitamin D concentration on RA and JIA outcomes.
| Author et al., year | Country Type of study | Number of participants,F:M Age | Disease duration | Impact on disease outcomes |
|---|---|---|---|---|
| RA | ||||
| Hajjaj-Hassouni et al., 2017 (COMORA study) (36) |
Asia, Europe, North America, South America, Africa Post-hoc analysis of a Cross-sectional study |
1,413 RA patients 4.86:1 57.9 ± 12.8 |
8.3 (3.6–15.2) years | Serum 25(OH)D levels and DAS28 were inversely correlated (r = -0.104; p < 0.001) |
| Lin et al., 2016 (38) | Asia, Europe, North America, South America, Africa, 24 studies Systematic review and meta-analysis |
3,489 | N/A | Serum 25(OH)D levels and DAS28 were inversely correlated (r = -0.13; p = 0.02). |
| Song et al., 2012 (46) | Europe, North America, Middle East Systematic review and meta-analysis 8 studies |
2,885 RA patients 1,084 controls |
N/A | 7 out of 8 studies reported an inverse relationship between vitamin D levels and DAS28 |
| Lee and Bae, 2016 (37) | Asia, Europe, South America, Africa 15 Case-control studies |
924 RA patients | N/A | Inverse correlation between vitamin D levels and DAS28 (r = -0.278, p < 0.001) |
| Higgins et al., 2013 (47) | UK Cross-sectional study |
176 RA patients 3:1 64 (22–89) |
12 (1–37) years | No significant correlation between vitamin D levels and DAS28 with or without GVAS. Significant inverse correlation between vitamin D levels and VAS-pain (r = -0.249, p = 0.013) |
| Pakchotanon et al., 2016 (48) | Thailand Cross-sectional |
239 RA patients 6.9:1 58.85 ± 12.56 |
112.79 ± 203.03 months | No correlation between vitamin D levels and DAS28. |
| JIA | ||||
| Pelajo et al., 2012 (49) | US Cross-sectional study |
154 JIA patients 1.56:1 10.6 ± 4.5 |
28 (6–66) months | No correlation between 25(OH)D levels and JADAS27 JADAS27 was higher in polyarticular JIA than oligoarticular JIA (p = 0.003) |
| Stagi et al., 2014 (43) | Italy Cross-sectional study |
152 JIA patients 3.1:1 16.2 ± 7.2 |
129.5 ± 11.11 months | Patients with active disease and frequent relapses have significantly lower 25(OH)D levels than those without (p < 0.005) |
| Çomak et al., 2014 (50) | Turkey Cross-sectional |
47 JIA patients 1.56:1 9.3 ± 3.9 |
28 months | Negative correlation between 25(OH)D levels and disease activity (r = -0.37, p = 0.01) JADAS27 is greater in patients with 25(OH)D levels <15 ng/ml than those >15 ng/ml (p = 0.003) |
| Shevchenko and Khadzhynova, 2019 (51) | Georgia Cross-sectional |
69 JIA patients 1.9:1 10.7 ± 4.5 |
4.1 ± 1.1 years | A significant relationship between vitamin D level and number of active joints. |
DAS28, disease activity score assessing 28 joints; JADAS 27, juvenile arthritis disease activity score assessing 27 joints; JIA, juvenile idiopathic arthritis; RA, rheumatoid arthritis; VAS, visual analogue scale; N/A, not available; 25(OH)D, 25-hydroxy vitamin D.