Vitamin d status and cardiometabolic risk factors in long-term psychiatric inpatients

Low vitamin D levels are common in psychiatric patients, but a need for vitamin D supplementation in these individuals remains controversial. Low vitamin D levels are reportedly associated with high prevalence of cardiometabolic risk factors, and both are common in psychiatric patients, but the relationship between diagnosis and severity of illness and cardiometabolic risk status and the effect of vitamin D treatment on them is not known. We studied these relationships and effect of vitamin D(3) treatment on them in 290 long-term psychiatric inpatients.

All patients admitted to the hospital during April 2009-March 2010 who agreed to 25-hydroxyvitamin-D testing were included. Serum 25-hydroxyvitamin D level, Brief Psychiatric Rating Scale (BPRS) score, body mass index, blood pressure, and fasting levels of blood glucose, triglycerides, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were measured at baseline, and changes after vitamin D(3) treatment for up to 12 months were observed. For the purposes of this study, 25-hydroxyvitamin-D levels < 32 ng/mL were considered as "low"; < 20 ng/mL, as "insufficient"; and < 12 ng/mL, as "deficient."

A serum 25-hydroxyvitamin-D level < 32 ng/mL was found in 90.0% of patients, and a level <20 ng/mL was found in 48.6% of patients. A BPRS score > 36 was present in 56.0% of patients; obesity, in 75.7%; hypertension, in 44.8%; low HDL-C, in 43.6%; high triglycerides, in 31.2%; high LDL-C, in 17.8%; and increased glucose, in 14.6%. Serum 25-hydroxyvitamin-D levels correlated poorly with BPRS score and the other variables listed above (R, -0.02 to -0.22). After vitamin D(3) treatment, 25-hydroxyvitamin-D level increased to ≥ 20 ng/mL in all patients and ≥ 32 ng/mL in 85% of patients, but despite > 124% increase in mean 25-hydroxyvitamin-D level, mean improvement in other variables was < 12%.

Nearly half of our patients had vitamin D levels < 20 ng/mL, putting them at risk for poor bone health and requiring vitamin D supplementation. Cardiometabolic risk factors were also highly prevalent, but correlated poorly with vitamin D levels in their severity. Increasing vitamin D levels to ≥ 32 ng/mL was not associated with improvement in BPRS score or any cardiometabolic risk factor, emphasizing that intensification of therapeutic measures other than vitamin D supplementation is required.