Vitamin D plasma levels during summer in a psychiatric population are comparable to the winter levels of healthy individuals.

INTRODUCTION Our understanding of the influence of a low plasma-25(OH) vitamin D3 (25-OHD) level on psychiatric disease is growing. Very limited information is available about the 25-OHD level in psychiatric populations. This study was initiated to determine which patients should have their 25-OHD levels analysed and who would require treatment. MATERIAL AND METHODS This retrospective, cross-sectional study comprised patients admitted for hospitalisation at Mental Health Centre Frederiksberg from 25 May to 9 September 2010. A total of 170 patients and their corresponding 25-OHD results were included. RESULTS Of the 170 patients, 55% (n = 93) were women and 45% (n = 77) were men. Thirteen patients (8%) had severe to moderate 25-OHD deficiency, 59 had insufficiency and 98 had a normal 25-OHD. In total, 42% of the results were abnormal. No differences were detected according to sex, age or diagnosis group. No correlation was found between 25-OHD and cobalamine, thyroid-stimulating hormone or Ca2+. CONCLUSION It should be possible from the patient history, i.e. geographical or lifestyle issues, to identify patients at risk of 25-OHD deficiency or insufficiency, and only perform the 25-OHD test on these patients. A vitamin D supplement may be considered for all high-risk patients even without knowing their exact 25-OHD values. This would allow such patients to be treated as recommended (the Danish Health and Medicines Authority). The recommended treatment for "patients who do not get out and who avoid the sun" is a daily 10 μg vitamin D supplement. Some of the patients may preferably be treated as "nursing home residents" and thus be given a 20 μg vitamin D supplement and 800-1,000 mg calcium daily. FUNDING We received DKK 5,000 from "Helge Hørrings Fond til fremme for skizofreniforskning". This amount covered statistical assistance. TRIAL REGISTRATION not relevant.