As well as many physical health benefits, Vitamin D is also known to have an effect on the brain:

A healthy supply of Vitamin D seems to be beneficial to our mental health and there are suggestions that having sufficient Vitamin D at a very young age might protect the brain from a range of conditions later in life, including MS.

Studies have shown that antidepressants work better when there is Vitamin D sufficiency, that low Vitamin D is linked to depression, and even that there is an association between suicidal tendencies and low Vitamin D.

A systematic review from 2014 taking only correctly designed studies concluded: Meta-analysis of studies without biological flaws demonstrates that improving Vitamin D levels improves depression.

Looking to our futures, a large prospective, population-based study from 2014 showed that low Vitamin D levels below 50 nmol/l are associated with increased risk of dementia.