Vitamin D deficiency and suicidal ideation: A cross-sectional study of 157, 211 healthy adults

Objectives: Vitamin D deficiency has been reported to be associated with various neuropsychiatric disorders. However, there are few studies addressing deficient vitamin D levels and suicidal ideation. Methods: Serum vitamin D of 157,211 Korean adult participants were measured using electrochemiluminescence immunoassay. A self-reported questionnaire was used to assess whether participants experienced suicidal ideation. Logistic regression model was used to estimate the odds ratio (OR) of suicidal ideation according to vitamin D levels. The regression was adjusted for a range of covariates. Results: Compared with sufficient vitamin D levels (>= 20 ng/mL), deficient vitamin D levels (< 10 ng/mL) were significantly associated with the risk of suicidal ideation (OR = 1.138, 95% Cl = 1.027-1.262). However, the OR of suicidal ideation was not significantly different between the vitamin D insufficient group (10-19.99 ng/mL) and sufficient group (>= 20 ng/mL) (OR = 0.988, 95% Cl = 0.932-1.047). Conclusion: Deficient vitamin D levels were significantly associated with the risk of suicidal ideation. However, the risk of suicidal ideation was not significantly different between the vitamin D insufficient group and sufficient group.