Association between serum levels of bioavailable vitamin D and negative symptoms in first-episode psychosis

Abstract

Total vitamin D levels had been commonly reported to be lowered in patients with chronic psychotic illnesses in countries from the higher latitudes. However, studies on patients with first episode psychosis (FEP) are limited. In this study we investigated serum concentrations of total and bioavailable vitamin D levels in FEP patients compared to healthy controls and the association between symptom severity and vitamin D components. A total of 31 FEP patients and 31 healthy controls were recruited from Institute of Mental Health, Singapore. FEP patients were identified using Structured Clinical Interview for DSM-IV Axis I disorders (SCID-1) and severity symptoms were assessed using the positive and negative syndrome scale (PANSS). Sera from participants were analyzed for total vitamin D, vitamin D-binding protein (DBP) and bioavailable vitamin D. Linear regressions were performed to examine the associations between serum total and bioavailable vitamin D and the PANSS subscales. Current study noted a significantly lower bioavailable vitamin D was in the FEP group and an association between bioavailable vitamin D and negative symptoms in FEP patients in a population with a consistent supply of sun exposure throughout the year.

Vitamin D and clinical symptoms in First Episode Psychosis (FEP): A prospective cohort study

“…We identified that 80% (n=134) had suboptimal vitamin D levels (<20ng/L) at first contact for psychosis, a much higher proportion than the previously reported 50% (n=10) with vitamin D levels <30ng/ml at FEP (Graham et al, 2015). We identified a mean vitamin D level of 13.8ng/ml (n=168) at study recruitment, much lower than the previously identified mean vitamin D levels in FEP of 28.2 ng/ml (n=20) (Graham et al, 2015), 61.7 ng/ml (n=31) (Yee et al, 2016) and 44.8 ng/ml (n=71) (Nerhus et al, 2015). This finding may be a reflection of the ethnicity distribution of our sample.…”

“…The lack of an association between vitamin D levels (both categorical and continuous) and negative symptoms of psychosis at baseline, but the identified association with negative symptoms at 12 months, raise the possibility that low vitamin D at onset of psychosis may be associated with the later emergence of negative symptoms. Like previous work in FEP, we failed to identify a cross sectional relationship between vitamin D levels and positive (Graham et al, 2015;Nerhus et al, 2015;Yee et al, 2016) or negative symptoms (Nerhus et al, 2015).…”

“…Low vitamin D levels were associated with negative symptoms and more severe cognitive deficits in 20 people with first episode schizophrenia (FES) (Graham et al, 2015). These findings were supported by a cross sectional study of 31 FEP patients, in which a similar inverse correlation between vitamin D levels and negative symptoms was identified (Yee et al, 2016). A somewhat larger study with 71 FEP patients did not identify significant correlations between vitamin D and psychotic symptoms, but did identify significant correlations with depressive symptoms (Nerhus et al, 2015).…”

Effects of Atypical Antipsychotics on Neuroactive Vitamins in Patients With Schizophrenia

“…Some studies concluded that significantly lower vitamin D concentrations and higher vitamin D deficiency rate were observed in the schizophrenic group compared with the matched control group, 8,28,29 which were consistent with our conclusions. However, others reported statistically undifferentiated vitamin D concentrations in the schizophrenic group, such as the case-control studies from Yee et al, 9 Graham et al, 30 and Norelli et al 31 All the contributions showing no significant correlation adopted routine immunologic methods to determine vitamin D concentrations, which could lead to inaccurate results due to the inevitable presence of cross reaction and incomplete extraction of 25(OH)D from vitamin D-binding protein. 32 LC-MS/MS has been considered the reference method of vitamin D quantification.…”

“…Evidence from a rapidly increasing number of observational studies exhibited the essential neuroprotective effects of these vitamins. For instance, vitamin D has presented a wide spectrum of neurobased functions, such as influencing neurotransmitter expression and neuroplasticity development, [8][9][10] as well as facilitating neuronal differentiation and maturation. 11 In consideration of the research findings that oxidative stress was believed to contribute to schizophrenia pathophysiology, 12,13 the well-known antioxidant vitamins (vitamins A and E) were likely to play important protective roles in schizophrenia by preventing oxidative damage.…”