Vitamin D and Mortality: an Individual Participant Data Meta-analysis of Standardized 25-hydroxyvitamin D

Vitamin D deficiency is a risk factor for mortality but existing data are limited by missing standardization of laboratory methods for 25-hydroxyvitamin D (25\[OH\]D). In a European consortium of eight cohort studies we use protocols of the Vitamin D Standardization Program (VDSP) to obtain standardized 25(OH)D data. Individual participant data (IPD) meta-analyses using a one step procedure will be performed to study associations of original and standardized 25(OH)D with all-cause, cardiovascular, and cancer mortality.