Vitamin D Deficiency and Depression

Depression is a severe common mental disorder that affects you negatively[1,2]. Did you know it is estimated that 5% of adults suffer from depression[2]? It overshadows all your interests, feelings, and daily activities like working, eating, and sleeping [1,3].

The Role of Vitamin D in Depression

The most common treatment for depression is anti-depressants and psychotherapy [4]. However, in recent years there has been a lot of discussion regarding nutritional deficiencies and their role in mental health disorders[4,5]. Increasing evidence-based research has signified the role of vitamin D in the pathobiology and treatment of depression. Presently, there are at least three associations reported[5]. Firstly, Vitamin D is said to play a key role in mood regulation via the presence of its receptors in the brain. Vitamin D metabolites can cross the blood-brain barrier and access these receptors[5,6]. Secondly, the role of vitamin D in reducing inflammation by immune-modulatory mechanism [7]. And thirdly, the neuroprotective properties of vitamin D. Depression is marked by the increase in levels in pro-inflammatory cytokines. This in turn leads to a series of reactions that damage the neurons in the brain. Anti-depressants work by modulating the neurotropic system and enhancing neurogenesis. Preclinical studies demonstrated that Vitamin D regulates concentration in animal models having neurodegenerative disorders [8–10].

On the contrary, depression can also cause a deficiency of Vitamin D. An individual suffering from depression is less likely to go outdoors. It leads to less exposure to the sun which is one of the primary ways it is metabolized in the body [8,11]. Loss of appetite can also lead to nutritional vitamin D deficiency[12].

Can Vitamin D be Used in Treatment for Depression?

We now know that insufficiency of vitamin D possibly plays an important role in depression. However, using Vitamin D supplements as an effective treatment is not yet possible due to the research gaps [13,14]. What we currently know is mostly based on animal-based studies and few human-based studies [11]. There are varying results from these studies that suggest a relationship between vitamin D and depression but no concluding evidence to support it. As a consequence, these gaps can be addressed in future trials based on patients with depression and vitamin D deficiency [11].