Table 2.
Beneficial | Null Effect | Harmful | |
---|---|---|---|
Overall | 13 *,†,‡ | 14 | 3 |
Baseline vitamin D | |||
All deficient | 3 * | 1 | 0 |
Mean/Median deficient | 11 *,†,‡ | 10 | 3 |
Vitamin D supplementation | |||
Daily Oral | 11 *,† | 7 | 0 |
Outcome ascertainment | |||
At-event reporting | 7 ‡ | 7 | 2 |
* trial reporting a U-shaped relationship by vitamin D level; † trial reporting a significant effect by Poisson but not negative binomial distribution; ‡ trial reporting significant results after adjustment for baseline characteristics.