Mean plasma 25(OH)D levels and baseline characteristics for cases and controls.

1To convert to nanomoles per liter, multiply by 2.496.2There was no significant difference between suicide cases and matched controls in 25(OH)D levels, either not adjusted for season of blood sample collection (t494 = 0.41, p = 0.68), or adjusted for season of blood sample collection using a waveform algorithm (t494 = 0.43, p = 0.67).3Only bimonthly categories were available for season of blood draw, as the dates of both blood collection and of suicide were provided from AFHSC in two month intervals to preserve anonymity of the suicide casualties.4Significant difference between suicide cases and matched controls based on a paired t-test (t494 = 3.68, p = 0.0003).5Significant difference in frequency between cases and matched controls (X2 = 12.2, p = 0.0005).