Is this D vitamin to worry about? Vitamin D insufficiency in an inpatient sample

Objective: The aim of the present study was to investigate the relationship between reduced serum vitamin D levels and psychiatric illness. Method: This study was an audit of serum 25-hydroxyvitamin D (25-OHD) levels measured routinely in a sample of 53 inpatients in a private psychiatric clinic. These levels were compared with those of controls without psychiatric illness. Results: The median levels of serum 25-OHD were 43.0 nmol L-1 (range 20-102 nmol L-1) in the patient population, 46.0 nmol L-1 (range 20-102 nmol L-1) in female patients (n = 33) and 41.5 nmol L-1 (range 22-97 nmol L-1) in male patients (n=20). The proportion of vitamin D insufficiency (serum 25-OHD <= 50 nmol L-1) in this patient population was 58%. Furthermore, 11% had moderate deficiency (serum 25-OHD <= 25 nmol L-1). There was a 29% difference between mean levels in the patient population and control sample (geometric mean age- and season-adjusted levels: 46.4 nmol L-1 (95% confidence interval (CI) = 38.6-54.9 nmol L-1) vs 65.3 nmol L-1 (95% CI = 63.2-67.4 nmol L-1), p < 0.001). Conclusion: Low levels of serum 25-OHD were found in this patient population. These data add to the literature suggesting an association between vitamin D insufficiency and psychiatric illness, and suggest that routine monitoring of vitamin D levels may be of benefit given the high yield of clinically relevant findings.