Low vitamin D status and suicide: a case-control study of active duty military service members

PLoS One. 2013;8(1):e51543. doi: 10.1371/journal.pone.0051543. Epub 2013 Jan 4.

Abstract

Objective: Considering that epidemiological studies show that suicide rates in many countries are highest in the spring when vitamin D status is lowest, and that low vitamin D status can affect brain function, we sought to evaluate if a low level of 25-hydroxyvitamin D [25(OH)D] could be a predisposing factor for suicide.

Method: We conducted a prospective, nested, case-control study using serum samples stored in the Department of Defense Serum Repository. Participants were previously deployed active duty US military personnel (2002-2008) who had a recent archived serum sample available for analysis. Vitamin D status was estimated by measuring 25(OH) D levels in serum samples drawn within 24 months of the suicide. Each verified suicide case (n = 495) was matched to a control (n = 495) by rank, age and sex. We calculated odds ratio of suicide associated with categorical levels (octiles) of 25(OH) D, adjusted by season of serum collection.

Findings: More than 30% of all subjects had 25(OH)D values below 20 ng/mL. Although mean serum 25(OH)D concentrations did not differ between suicide cases and controls, risk estimates indicated that subjects in the lowest octile of season-adjusted 25(OH)D (<15.5 ng/mL) had the highest risk of suicide, with subjects in the subsequent higher octiles showing approximately the same level of decreased risk (combined odds ratio compared to lowest octile = 0.49; 95% C.I.: 0.315-0.768).

Conclusions: Low vitamin D status is common in active duty service members. The lowest 25(OH)D levels are associated with an increased risk for suicide. Future studies could determine if additional sunlight exposure and vitamin D supplementation might reduce suicide by increasing 25(OH) D levels.

Publication types

  • Research Support, N.I.H., Intramural

MeSH terms

  • Adult
  • Age Factors
  • Case-Control Studies
  • Female
  • Humans
  • Male
  • Military Personnel*
  • Odds Ratio
  • Risk Factors
  • Seasons
  • Sex Factors
  • Suicide*
  • Vitamin D / analogs & derivatives*
  • Vitamin D / blood
  • Vitamins / blood*

Substances

  • Vitamins
  • Vitamin D
  • 25-hydroxyvitamin D