Table 2 Subgroup analysis to investigate the effect of the type of vitamin K on the effect size of vitamin K combined with calcium on 431 lumbar spines BMD
Subgroup | Studies | SMD (95% CI) | I2 (%) | P |
|---|---|---|---|---|
Vitamin K type | Â | Â | Â | Â |
 K1 | 5 | 0.14 (− 0.02 to 0.29) | 65.4 | 0.021 |
 K2 | 5 | 0.30 (0.10 to 0.51) | 0 | 0.429 |
Vitamin K dose | Â | Â | Â | Â |
 ≤ 100 μg | 5 | 0.40 (0.20 to 0.61) | 49.9 | 0.092 |
 > 100 μg | 5 | 0.08 (− 0.08 to 0.23) | 0 | 0.584 |
Calcium dose | Â | Â | Â | Â |
 ≤ 1000 mg | 7 | 0.19 (0.05 to 0.32) | 62.3 | 0.014 |
 > 1000 mg | 3 | 0.26 (− 0.04 to 0.55) | 0 | 0.644 |
Follow-up time |  |  |  |  |
 ≤ 1 year | 6 | 0.38 (0.19 to 0.57) | 40 | 0.139 |
 > 1 year | 4 | 0.06 (− 0.10 to 0.22) | 0 | 0.496 |
Gender | Â | Â | Â | Â |
 Female | 8 | 0.26 (0.11 to 0.41) | 52.5 | 0.040 |
 Both | 2 | 0.08 (− 0.14 to 0.29) | 0 | 0.573 |