Published on:
28. Juli 2023
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Vitamin D, the power of the sun & its importance for our nervous system

The immense importance of vitamin D for our body, but also for our psyche, has long been underestimated. We explain here how the so-called sun hormone is linked to depressive moods and why it is currently particularly important to naturally refill the vitamin D tanks. 

The term vitamin D refers to the so-called calciferols, a group of fat-soluble vitamins. The two most important forms are vitamin D2 (ergocalciferol), which is found in very small doses in some plant-based foods, and vitamin D3 (cholecalciferol), which is also only found in small amounts in animal foods, but can be produced by the human body itself under the influence of sunlight or UVB radiation. The key point here is that the vitamin D produced by the body is stored in the liver as well as in fat and muscle tissue and can therefore - unlike water-soluble vitamins - be stored and supply the body for several months. 

While the involvement of vitamin D in bone metabolism and thus its importance with regard to diseases such as rickets or osteoporosis is well known and proven, in recent years more and more functions of this very special vitamin have been discovered and clinically tested. For example, vitamin D is also involved in other metabolic processes, in the formation of proteins and in the formation of many different genes, which has revealed information about the connections between chronic diseases and new prevention options. According to the specialist literature, the diseases that can be associated with low vitamin D levels include diabetes and autoimmune diseases as well as chronic pain conditions, cancer, cardiovascular problems, dementia and depression. As in so many medical areas, however, there are very different expert opinions on this topic too. 


Let the sunshine in. However, despite all the different viewpoints on vitamin D, its dosage, function and use, one thing is undisputed: especially in Central and Northern Europe, solar radiation is not strong enough all year round to provide the population with sufficient vitamin D. In addition to these climatic conditions, a vitamin D deficiency, which the majority of Central and Northern Europeans suffer from, is caused by the fact that we spend too little time in the sun due to our work or that we cover our skin with too much clothing or sun cream, so that no vitamin D can be produced. The sunny summer months from May to September in particular should be used to regularly expose the skin to a certain amount of UVB radiation in order to replenish our own reserves for the winter months. 


If that doesn't work, the vitamin D level should be balanced with appropriate supplements to prevent the first symptoms of a deficiency, such as chronic fatigue despite sufficient sleep and rest phases, poor wound healing, high susceptibility to infections, muscle and limb pain, hair loss, or migraines. Vitamin D is also particularly important during cold season, as it strengthens the immune system and can make the body more resistant to infections and allergies. Sufficient vitamin D is also essential for the nervous system, as a deficiency can promote diseases such as multiple sclerosis or dementia. Before taking additional supplements, however, it is particularly important to have your individual level checked first, as vitamin D is not water-soluble and therefore cannot be broken down immediately by the body, which is why an overdose can cause long-term damage. 

Mood enhancer & nerve strength. A chronically depressed and bad mood can be another symptom of a vitamin D deficiency - especially in the gray winter months. For example, depression has been linked to low vitamin D levels not only in older people, but also in younger women who suffer from the hormonal disorder PCOS, polycystic ovary syndrome. 

Several studies show that vitamin D is an important factor in our mental health. Adequate levels can help reduce the risk of depression and improve our mood. So, especially now, make sure you get some fresh air and plenty of sunlight. But beware, although optimizing vitamin D levels can make a positive contribution to mental health, it is nevertheless important to note that vitamin D alone does not work miracles and cannot cure depression. If you are experiencing severe depressive symptoms, it is essential to seek professional help to get the best possible support. 



RKI – Robert Koch Institute,,is%20the%20involvement%20in%20bone%20metabolism. 

Center for Health, 

Gowda, U., Mutowo, MP, Smith, BJ, Wluka, AE, & Renzaho, AMN (2015). Vitamin D supplementation to reduce depression in adults: meta-analysis of randomized controlled trials. Nutrition, 31(3), 421-429. 

Jääskeläinen, T., Knekt, P., Suvisaari, J., Männistö, S., Partonen, T., & Sääksjärvi, K. (2015). Higher serum 25-hydroxyvitamin D concentrations are related to a reduced risk of depression. Journal of Nutrition, 113(09), 1418-1426. 

Kjærgaard, M., Waterloo, K., Wang, CEA, Almås, B., Figenschau, Y., Hutchinson, MS, ... & Aukrust, P. (2019). Effect of vitamin D supplementation on depression scores in people with low levels of serum 25-hydroxyvitamin D: nested case–control study and randomised clinical trial. British Journal of Psychiatry, 214(5), 260-267. 

Okereke Ol et al. (2016): The role of vitamin D in the prevention of late-life depression. In: Journal of Affective Disorders, 198, 1-14.