A new study suggests that a lack of vitamin D can be a serious factor in depressive episodes.
This is particularly important for UK citizens, as a deficit of the vitamin is common in British people, particularly in winter.
Britons are advised by doctors to take supplements of the vitamin during the darker months of the year, when insufficient amounts of sunlight can be available for absorption.
Although vitamin D is commonly found in foods, with oily fish a particularly rich source, most people require some access to sunshine in order to generate acceptable levels of the substance.
In the new study, which was revealed at the International Early Psychosis Association in Milan, scientists tested vitamin D levels among 225 patients being treated for psychotic disorders and another 159 well people.
Researchers found a significant association between low levels of vitamin D and “higher levels of negative symptoms and of depression” among people with psychosis.
They also found a significant link to reduced verbal fluency and cognitive impairments.
In a paper in the journal Schizophrenia Research, the researchers, from Norway suggested that vitamin D could be used to help treat patients.
“In a clinical setting, this could support vitamin D as adjuvant therapy in treating co-morbid depressions in psychotic disorders. The associations between low vitamin D levels and increased negative and depressive symptoms, and decreased [mental] processing speed and verbal fluency are good arguments for planning large scale randomised controlled studies in target populations, in order to reach conclusions about vitamin D’s potential beneficial effect in psychotic disorders.”
Further studies are currently being conducted with MRI scanners in order to attempt to understand the impact of vitamin D on the human brain.
Dr Peter Selby, of Manchester University, who has studied vitamin D, concurs with the findings of the research that vitamin D could be linked with depression.
“We know vitamin D levels are important for things like muscle function as well as bone function. And muscle function isn’t a million miles removed from nerve function. A lot of people with low vitamin D levels…they’ve not quite as much get up and go, they’ve got a few more aches and pains, that sort of thing.”
But Selby also believes that researchers must investigate the subject further in order to establish the precise influence of the vitamin on mood.
“If you are depressive, you are less likely to get out and about, you’re less likely to see the sun, and therefore have less vitamin D. It’s difficult to tell which is the chicken and which is the egg here.”