This site uses cookies to store information on your computer. Learn more x


Providing perspectives on recent research into vitamins and nutritionals


Will new research on the interplay between low vitamin D levels and negative psychotic symptoms affect the market for antidepressants?

By Rob Winwood

New scientific findings from Norway (1) reveal a strong association between low vitamin D levels in the blood and increased negative psychotic symptoms and depression. Negative psychotic symptoms are loss of positive interpersonal communication functions, such as the lack of emotions and interest in other people and of ideas. In Europe, around 37% of the population is concerned about mental health (2).

The active metabolite of vitamin D, 1,25-dihydroxy-vitamin D, is able to cross the blood-brain barrier and is found in the human brain. Vitamin D is believed to be important in the process of neurodevelopment and the causation of neuropsychiatric disorders (3). However, 88% of the world’s population have a sub-optimal vitamin D status (4). The incidence of vitamin D deficiency is even higher in people suffering from psychotic disorders, than the population at large (5).

A paper published in early 2015 presents findings on how vitamin D regulates the enzyme that converts tryptophan into serotonin and discusses how serotonin regulates executive function (including decision-making and long-term planning), sensory gating (which is the ability to filter out extraneous sensory information) and social behaviour. Attention deficit hyperactivity disorder, bipolar disorder, schizophrenia, and impulsive behavior all share defects in these functions (6). The strongest links between low vitamin D status and mental illness have previously been analysed and found to be in those people who have been suffering depression (7,8).

The recent study from South Norway of 358 patients (part of the Thematically Organised Psychosis or TOP cohort) who have suffered one or more psychotic episodes, has revealed a strong association between low blood vitamin D levels (measured as plasma S-25(OH)D) and increased negative psychotic symptoms and depression. Roughly two thirds of the patients were diagnosed as being in schizophrenic spectrum, whilst roughly one third were diagnosed as bipolar. Negative psychotic symptoms are those where the loss of positive interpersonal communication functions e.g. lack of emotions, monotonic speech, lack of interest in other people, lack of ideas and lack of spontaneity. This association has also been seen in two previous smaller studies (9). The findings are important, as these negative psychotic symptoms are particularly difficult to treat and very distressing for the patient.

The association between low vitamin D serum levels and depression/negative psychotic symptoms was particularly strong when measurements were made in the winter months and among those of non-Nordic ethnic origin, where presumably the majority have relatively highly pigmented skin. The lack of sun exposure and high skin melatonin levels are both known to depress serum vitamin D levels. It has recently been shown that vitamin D is important in serotonin synthesis, hence a low level will cause depression (10). Many anti-depressant medications work by increasing the amount of monoamines, such as serotonin, in the brain. Therefore, researchers suggest that vitamin D may also increase the amount of monoamines, which may help treat depression.

A study on consumer health concerns recently conducted in Europe (11), revealed that 37% of the population is concerned about mental health, whereof around 70% of young and older adults are worrying about depression and anxiety. At the same time the positive association of vitamin D for health is relatively high (67%), and so is the awareness about the general role nutrients may play for mental and cognitive health (22%).

Whilst the findings of the Norwegian studies are important, it is now necessary to conduct an intervention trial among patients suffering psychosis. The aim is to determine if their symptoms can be reduced and what role vitamin D may play.

For more information

“Emerging health benefits of vitamin D” – register HERE and attend the webinar (available on demand) to learn more about the latest science

“Implications of vitamin D deficiency“ – download the whitepaper HERE

“Trends in health concerns across Europe, Middle East and Africa” – download the whitepaper HERE


(1) Nerhus et al.; “Low vitamin D is associated with negative and depressive symptoms in psychotic disorders”; Schizophr. Res. 2016,

(2) European Study on Consumer Health Concerns

(3) Cui et al.; “Vitamin D and the brain: key questions for future research”; J. Steroid Biochem. 2015.

(4) Status below 75nmol/L: vitamin D deficiency map, developed the International Osteoporosis Foundation and DSM

(5) Belvederi Murri et al.; “Vitamin D and psychosis: mini meta-analysis”; Schizophr. Res. 2013.

(6) Patrick et al.; “Vitamin D and the omega-3 fatty acids control serotonin synthesis and action, part 2: relevance for ADHD, bipolar, schizophrenia, and impulsive behavior”; FASEB 2015.

(7) Anglin et al.; “Vitamin D deficiency and depression in adults: systematic review and meta-analysis”; Br. J. Psychiatry 2013.

(8) Gowda et al.; “Vitamin D supplementation to reduce depression in adults: Meta-analysis of randomized controlled trials”; Nutrition, 2015. 31(3): p. 421-429.

(9) Cieslak et al.; “Low vitamin D levels predict clinical features of schizophrenia”; Schizophr. Res. 2014, and Graham et al.; “Relationship of low vitamin D status with positive, negative and cognitive symptom domains in people with first-episode schizophrenia”; Early Interv. Psychiatry 2015.

(10) Patrick et al.; “Vitamin D hormone regulates serotonin synthesis. Part 1: relevance for autism”; FASEB J. 2014.

(11) DSM survey, conducted March 2016