IPD analysis on dose-effect relationships of vitamin D treatment on risk of death. Note that none of the included studies used a daily dose between 10 and 20 μg. All studies and stratified by whether vitamin D was provided alone (Vit D alone) or in combination with calcium (Vit D + calcium). Data represent adjusted HR (95% CI). The Smith study using an average daily dose of 20 μg vitamin D2 was regrouped into the low-dose (10 μg/d) group.