Professor/Research Scientist Wegmans School of Pharmacy, St John Fisher College Rochester, United States
Background: Vitamin D insufficiency and deficiency are prevalent including among US servicemembers. Low serum levels are associated with suicidal behavior and depressive symptoms, however population studies of serum, supplementation and suicidal behavior are needed.
Objectives: To test the association between Vitamin D supplementation, 25(OH) blood serum levels, suicide attempts, and intentional self-harm in US veterans.
Methods:
Design: A cohort study of US veterans receiving new vitamin D supplementation in the Department of Veterans Health Affairs (VHA) (Corporate Data Warehouse (CDW) were followed for 24 months. Veterans with any Vitamin D3 (cholecalciferol) or Vitamin D2 (ergocalciferol) fill between 2010 and 2018 were matched 1:1 to untreated controls by demographics and medical histories. Setting: Department of Veterans Health Affairs (VHA). Exposures: Vitamin D3 (cholecalciferol) or D2 (ergocalciferol). Main Outcome Measures: Inpatient or emergency room admissions for suicide attempt or self-harm ICD-9/10 codes. Statistical analysis: Cox proportional hazards regression estimated the time from the index fill to the first suicide attempt or intentional self-harm. Analyses were repeated in stratified samples by race, gender, blood levels (0–19 ng/ml, 20–39 ng/ml, and 40+ ng/ml), and mean daily dose.
Results: Vitamin D3 and D2 were associated with reductions in suicide attempt and self-harm of 45% and 48%, respectively ((D2 Hazard Ratio (HR) = 0.512, [95% CI, 0.457, 0.574]; D3 HR = 0.552, [95% CI, 0.511, 0.597])). Supplemented Black veterans and those with the lowest serum levels were at ~64% lower risk relative to controls (Black Veteran HR: 0.362 [95% CI: 0.298,0.440]; 0–19 ng/ml HR: 0.359 [95% CI: 0.215,0.598]). Higher vitamin D doses were associated with greater risk reductions than lower doses (Log Average Dosage HR: 0.837 [95% CI: 0.779,0.900]).
Conclusions: Vitamin D2 and D3 supplementation were associated with important reductions in risk of suicide attempt or self-harm presenting to emergency rooms and hospitals among VHA veterans. The greatest benefits were seen in Black veterans and those with vitamin D deficiency.
