Two thoughts often come to mind when a person hears the term, "vitamin D,": bone health and depression. Although it's common knowledge that vitamin D from direct sun exposure can help lift a person's mood, care should be taken not to assume that it's treatment or cause for depression or any other mental health condition. Mental and physical health conditions can be as individualistic as fingerprints. So it's best not to assume that vitamin D deficiency will automatically cause or be the result of depression or anxiety. Although vitamin D is essential, its specific effects on mental health have yet to be confirmed one way or the other (see ref 1) .
A Picture of Vitamin D
The human body uses vitamin D nutrients to help with calcium absorption. It might also help with the prevention or treatment of type 2 diabetes, cancer, multiple sclerosis, and more medical conditions (see ref 4). Direct sunlight helps the body produce vitamin D, and it can be absorbed naturally from foods like fatty fishes, mushrooms, cheeses, liver, and egg yolks. Low amounts of vitamin D can cause bones to ache and muscles to feel weak. If there's too much vitamin D in a person's bloodstream, that person can feel fatigued, disoriented, nauseous, or experience a rapid heartbeat.
Vitamin D and Depression
Although insufficient vitamin D intake doesn't automatically indicate that a person will suffer from depression, a lack of vitamin D has been found to contribute to symptoms related to depression (see ref 2). In a "PLoS One" study published in September 2015, patients with depression and a vitamin D deficiency experienced more symptoms of depression than those with only insufficient levels of vitamin D. For example, these patients would have been found to be more sad, fatigued, or have more difficulty concentrating than other patients. They may have also lost enjoyment for things that used to give them pleasure. But keep in mind that these individuals had been hospitalized with a diagnosis of a current episode of depression.
Vitamin D and Anxiety
A person experiencing anxiety might feel restlessness, nausea, experience an increased body temperature, or find themselves fidgeting. It's understandable for a person experiencing such symptoms to seek relief from an accessible nutrient. Unfortunately, very little research exists explaining any relationship between vitamin D and anxiety. One study published by "PLoS One" in 2011, found no distinctive differences between young adults given a vitamin D supplement versus those who were not (see ref 3). Their moods were not altered by vitamin D.
Since symptoms for too much or too little vitamin D are similar to symptoms experienced by those with depression and/or anxiety, it's understandable why many believe there might be a link between the three. Studies show that vitamin D might help improve moods for people with depression, but there seems to be no relationship at all between vitamin D and individuals experiencing anxiety. If you find that you're experiencing persistent symptoms of depression and/or anxiety or symptoms of low or high vitamin D levels, it's best to contact your physician or mental health counselor for a consult.