Table 5.
Overlap between meta-analyses of observational studies and vitamin D supplementation randomised controlled trials
| Disease outcome | Observational | Randomised controlled trials | Concordant direction | CI excluded null | ||||
|---|---|---|---|---|---|---|---|---|
| Metric | Effect size (95% CI) | Metric | Effect size (95% CI) | Both | Observational only | |||
| Cardiovascular disease102 130 | OR | 0.66 (0.57 to 0.77) | OR | 0.95 (0.86 to 1.05) | Yes | No | Yes | |
| Hypertension/blood pressure104 127 | OR | 0.70 (0.58 to 0.86) | WMD | −2.39 (−5.7 to 1.92) | Yes | No | Yes | |
| Birth weight/ risk of low birth weight36 61 | WMD | 130.9 (75.1 to 186.7) | OR | 0.4 (0.23 to 0.71) | Yes | Yes | No | |
| Birth length36 112 | WMD | 0.19 (−0.26 to0.65 ) | WMD | 0.97 (−0.41 to 2.34) | Yes | No | No | |
| Head circumference36 112 | WMD | 0.05 (−0.24 to 0.34) | WMD | 0.43 (0.06 to 0.79) | Yes | No | No | |
| Small for gestational age36 61 | OR | 0.54 (0.44 to 0.67) | OR | 0.67 (0.4 to 1.11) | Yes | No | Yes | |
| Mortality in CKD patients84 120 | OR | 0.86 (0.81 to 0.92) | OR | 1.4 (0.38 to 5.15) | No | No | Yes | |
| All cause mortality66 110 | OR | 0.72 (0.66 to 0.78) | OR | 0.91 (0.82 to 1.02) | Yes | No | Yes | |
| Fractures in older populations91 107 | OR | 0.31 (0.23 to 0.42) | OR | 1.01 (0.93 to 1.09) | No | No | Yes | |
| Hip fracture37 107 | Log ratio of geometric mean | −0.26 (−0.33 to −0.23) | OR | 1.15 (0.99 to 1.33) | No | No | Yes | |
CI=confidence interval; CKD=chronic kidney disease; OR=odds ratio; WMD=weighted mean difference.