Not many people would think that their depressive symptoms could be linked to a micronutrient deficiency, let alone that they could significantly reduce their symptoms by supplementing. This appears to be the case, however, as a recent meta-analysis has again shown that vitamin D supplementation can effectively reduce symptoms of depression.

How can vitamin D influence our mood?

By now, Vitamin D is known to be necessary for healthy bones, but it additionally performs several functions in our bodies that are unrelated to bone health. It's no coincidence that its specific functions are still being researched today, as its beneficial effects are being discovered in connection with an increasing number of diseases and problems.

We have all experienced that when it's nice and sunny outside, our mood improves, whereas, in winter or overcast, rainy weather, we often experience negative thoughts and moodiness. While the light itself has many positive effects, it also has a positive impact on our mood because of its role in vitamin D production.

When depressed, many people turn inward and do not like to leave their homes, so they get even less sunlight than before, which can exacerbate their vitamin D deficiency and further worsen their mood.

There have been several studies on the effects of vitamin D on depression, which show a clear link between vitamin D deficiency and the incidence of depression. Vitamin D supplementation itself has been tested in several studies to alleviate depressive symptoms, with mostly positive and sometimes mixed results. Vitamin D supplementation is most beneficial when someone is vitamin deficient, whereas it will not make a significant difference when adequately supplied. However, as it is a very common deficiency, it still proves an effective method in most cases.

Results of the new summary study

This meta-analysis and systematic review, published in April 2023, evaluated the pooled results of 18 clinical trials. They successfully demonstrated that vitamin D supplementation significantly alleviates depressive symptoms compared to placebo.

It was most effective in adults, especially those with major cases of depression, and surprisingly, it was effective regardless of initial vitamin D sufficiency.

The researchers concluded that the available evidence suggests that vitamin D supplementation may be a safe and effective therapy for depression.