Vitamin D deficiency associated with heightened depression, study suggests

A study published in the journal of Schizophrenia Research has suggested that a lack of vitamin D could be associated with increased symptoms of depression.

The news comes after the government recently recommended that everyone in Britain should take vitamin D supplements during the darker months.

Vitamin D deficiency is associated with bone conditions such as rickets and osteoporosis, but it can also affect muscle tissue and has been found to be associated with normal levels of dopamine, a chemical linked to mood, in the brain.

In the study, scientists tested vitamin D levels among 225 patients being treated for psychotic disorders and on 159 people who were mentally healthy. The study indicated that there was a significant link between low levels of vitamin D and increased levels of negative symptoms and depression. It also identified a significant link to reduced verbal fluency and cognitive impairments.

Researchers suggested: “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.”

Commenting on the report, Dr Peter Selby, of Manchester University, who has studied vitamin D, said it was plausible that low levels might have a depressive effect: “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 got quite as much get up and go, they’ve got a few more aches and pains, that sort of thing. 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.”