Hypovitaminosis D in psychiatric inpatients: clinical correlation with depressive symptoms, cognitive impairment, and prescribing practices.

OBJECTIVE: The association of hypovitaminosis D with measures of depressive symptoms and cognitive impairment remains unclear. This correlation and subsequent prescribing practices of vitamin D supplementation were evaluated in a population of psychiatric inpatients.

METHODS: A retrospective study was conducted of 548 patients with a serum 25-hydroxyvitamin D [25(OH)D] level measured during hospitalization. Outcomes included the association of hypovitaminosis D with Patient Health Questionnaire (PHQ-9) and Folstein Mini-Mental State Exam (MMSE) scores, including an evaluation of vitamin D dosing upon hospital discharge.

RESULTS: Two hundred three patients (37%) had hypovitaminosis D. The majority [183 (90%)] had moderate (10-24 ng/mL), while 20 (10%) had severe hypovitaminosis D (<10 ng/mL). There was no significant association between hypovitaminosis D and PHQ-9 or MMSE scores (p = 0.107 and p = 0.271, respectively). Overall, 33% of patients with moderate hypovitaminosis D and 45% of patients with severe hypovitaminosis D were newly prescribed vitamin D or received a dose increase. Initiation of vitamin D or increased vitamin D dose was significantly higher in patients with hypovitaminosis D (p < 0.001).

CONCLUSIONS: No association was found between hypovitaminosis D and depressive symptoms or cognitive function. However, patients with hypovitaminosis D were more likely to be prescribed additional vitamin D at hospital discharge.