Figure 1.

CONSORT trial flowchart. * Out of 299 intervention subjects, 44 subjects were excluded from analysis because they were not on 5000 IU vitamin D3 per day for at least 60 days, a timeframe that is considered to be protective [25]. The resulting 255 subjects included subjects who completed the 9-month study period and early withdrawals. ** Employee Health was unable to locate 27 control subject records for unknown reasons. A possibility for missing records could be due to name changes over the course of the study. Another 38 control subjects were found to have been terminated from employment prior to the study observation period and were excluded from analyses (n = 2892 − 27 − 38 = 2827).