An Exploratory Study of Serum 25-Hydroxyvitamin D Concentration and Psychological Distress Among Aboriginal and Torres Strait Islander Peoples in Australia

Background/Objectives: The colonisation of Australia around 250 years ago left a significant enduring impact on the mental health of Aboriginal and Torres Strait Islander peoples. Vitamin D may play a role in modulating mental health as its receptors are present in the brain regions associated with mood and behaviour regulation. We aimed to conduct an exploratory study to investigate associations between serum 25-hydroxyvitamin D (25(OH)D) concentration and Kessler Psychological Distress Scale 5 (K5) low/moderate vs. high/very high psychological distress among Aboriginal and Torres Strait Islander peoples. Methods: We used cross-sectional data from the 2012–2013 Australian Aboriginal and Torres Strait Islander Health Survey. Binary logistic regression was used to test associations between serum 25(OH)D concentration and K5, adjusting for age, sex, education, remoteness, socioeconomic status, season, alcohol intake, and smoking (n = 1983). Results: There was no association between serum 25(OH)D concentration and K5 in the total population. In our exploratory analyses, higher serum 25(OH)D concentration (per 10 nmol/L) was significantly associated with 10% lower odds of high/very high levels of psychological distress among females. When stratified by remoteness, higher serum 25(OH)D concentration (per 10 nmol/L) was significantly associated with 11% lower odds of high/very high levels of psychological distress among those living remotely. Conclusions: The findings of this study suggest no association between serum 25(OH)D and K5 among the total population, but with some exploratory evidence of differences by sex and remoteness. Given the high prevalence of low vitamin D status among this population, promoting adequate vitamin D status remains an important public health issue.