Table 2.
Observational studies and its characteristics.
| Author (Year of publication, country) | Number of Sample | Male :Female (M/F) | Baseline age | Baseline 25OHD level (ng/ml) | Study design | Results | Conclusion |
|---|---|---|---|---|---|---|---|
| Heidari et al (2011, Iran)26 | 298 | NA | Knee OA 60.2 ± 12.9 years and controls 60.1 ± 10.2 years | Knee OA : 23.8 ± 18.8, Control :34.5. ± 29.6 ng/ml, | case control | significant association between Vitamin D deficiency and knee OA in young patients (aged<60 years) and suggested to measure serum vitamin D level in any patient with early Knee OA symptoms. | Vitamin D was associated with knee OA in patients aged <60 years. |
| Fang Fang Zhang et al (2015 USA)23 | 418 | 46.6:53.4(223/195) | 61 ± 9.2 | 26.2 ± 10.3 | cohort | Participants with low vitamin D [25(OH)D < 15 mg/L] had >2-fold elevated risk of knee osteoarthritis progression | vitamin D deficiency has a increased risk of knee osteoarthritis |
| Fevziye Onsal Malas et al (2013, UK)27 | 80 | 0:100(0/80) | 20 to 45 | 20 | cross sectional | distal femoral cartilage is thinner in patient with low vitamin D level(<10 ng/ml) when compared to patient with vitamin D level(>10 ng/ml | Vitamin D deficiency is associated with thinning of distal femoral cartilage. |
| JA Jansen et al (2013, UK)29 | 139 | 42:58(58/81) | 71.4 | 40 | cross sectional | 24% prevalence of VDD in patients with severe knee OA who were scheduled for knee arthroplasty | Vitamin D is associated with high prevalence in elderly patients with advanced knee osteoarthritis. |
| Mohamed A.Abu Maaty et al (25)2013, Egypt | 46 | 22:78(10/36) | 54.7 ± 3.2 | 25 ± 1.6 | Cross-sectional | low level of Vitamin were found with newly diagnosed OA of Knee in post menopausal Egyptian women(50-60yrs | Vitamin D deficiency is associated with new OA knee in post menopausal |
| Ding C et al (2009, Australia)31 | 880 | 50:50(440/440) | 61 | 52.8 | Cohort | No significant association between vitamin D and sunlight exposure in Knee ROA but significant association was found between knee cartilage loss and VDD. | Vitamin D and sunlight exposure were both associated with reducing knee cartilage loss and concluded that vitamin D had a protective effect in knee cartilage. |
| Felson DT et al (2007, USA)21 | 992 | Framingham: 46.9:53.1 BOKS radiographic follow-up: 58.6:41.4 BOKS MRI follow-up: 61.6:38.4 |
Framingham study: 53.1 8.7 BOKS with radiographic follow-up: 66.2 (9.3); BOKS with MRI follow-up: 66.5 (9.6) |
Framingham study: 19.7 ± 7.4; BOKS radiographic follow up:20.2 ± 8.3; BOKS with MRI follow up: 20.3 ± 8.3 | 2 prospective cohort studies | No significant association between vitamin D and ROA and Knee cartilage loss | Vitamin D was not related to the joint space narrowing(JSN) and cartilage volume loss in Frangminham(mean age 53.1 yrs) and BOKS(mean age 66.2yrs) |
| Muraki S et al (2011, Japan)22 |
787 | 49:51 (388/399) | 65.6 ± 2.7 | 42.5 | cross sectional | No significant association of polymorphism of VDR with radiological OA but low tertile level vitamin D is associated with knee pain than high tertile of vitamin D level | VDD is not associated with radiographic Knee OA but is associated with knee pain and association between genetic polymorphism of VDR and knee pain were very weak evidence. |
| Bergink AP et al (2009, Netherland)28 | 1248 | 58:42(728/520) | 66.2 (6.7) | 26.4 (10.8) | cohort | Significant association between JSN and Knee ROA progression with low tertile vitamin D. | Low vitamin D intake increases the risk of progression of knee ROA particularly in subjects with low baseline BMD |