How many times have you heard that you need sunshine and vitamin D? Of course, this is an expression for winter and places with cold and cloudy climates. In summer, you probably get enough sunlight. This means that your skin will produce vitamin D, a compound essential for life and health.
In Spain, we might think that, being a country with a sunny climate, everyone has enough vitamin D, but the data tells us otherwise. A study published by Nature Scientific Reports indicates that up to 75% of the Spanish population suffers from a vitamin D deficiency. How is this possible? A sedentary lifestyle, spending a lot of time indoors and looking at screens are determining factors.
Vitamin D deficiency can increase the risk of osteoporosis, cardiovascular disease, and muscle weakness, among other things. But deficiency also affects the brain. In winter, a lack of this vitamin is associated with seasonal affective disorder and depression, and while vitamin D supplementation alone is not enough to treat these disorders, it is known that a deficiency worsens symptoms.
What is vitamin D used for in the body?
Vitamin D in the body is primarily involved in bone and connective tissue regeneration, immune function, and many other cellular processes. Vitamin D is essential for the absorption and retention of calcium and phosphorus, which are essential for the formation and maintenance of strong bones and teeth. Without adequate vitamin D, bones can become thin, brittle, or deformed.
In the immune system, vitamin D enhances the effects of monocytes and macrophages, the white blood cells that are our body’s main defenses and protect us from bacteria, viruses and other infections. In addition, vitamin D is also necessary to regulate inflammation, which is an immune response that, if prolonged longer than necessary and becomes chronic, can cause serious health problems such as obesity, diabetes and cardiovascular disease.
Vitamin D and Brain Health
Knowing that inflammation is one of the causes associated with multiple psychological disorders, from depression to schizophrenia or bipolar disorder, it is easy to establish a relationship with an increase in inflammation due to vitamin D deficiency. That is to say, the lack of vitamin D can affect our health and mental well-being.
Some studies have shown that people with depression tend to have lower vitamin D levels. However, the evidence is conflicting as to whether vitamin D deficiency directly causes depression or is one of several factors involved. Doubts arise because while some research suggests that vitamin D supplements may help improve depressive symptoms, other studies have found no significant benefit, indicating that there are other causes.
The possible relationship between vitamin D and mood may have a lot to do with its role in the production of serotonin, a key neurotransmitter involved in mood regulation and the target of current antidepressants. Some studies have shown that vitamin D supplements improve mood and sleep quality, and the latter factor has a lot to do with mental health. In another trial, vitamin D supplements showed positive effects on improving anxiety, but had no effect on depression.
However, although vitamin D deficiency may be linked to lower serotonin levels and the development of depression and anxiety, giving more vitamin D does not automatically cure these disorders, nor does it improve symptoms of depression (in most cases).
Sun, food and mood
However, there are proven positive effects associated with increasing vitamin D through diet and sun exposure. For example, there is the possibility that the skin itself is able to synthesize not only vitamin D, but also serotonin directly, when exposed to sunlight. Another study of healthcare workers, who had little sun exposure due to their shifts, found that those who saw more sun had better mental health and better sleep quality.
Sleep may be another factor that indirectly mediates the relationship between vitamin D and mood. It is known that getting sun exposure in the morning helps you sleep better at night. On the other hand, increasing your vitamin D levels, whether through sun exposure or supplementation, can help you get better quality sleep, and therefore a better mood.
Sleep may be another factor that indirectly mediates the relationship between vitamin D and mood. It is known that exposure to sunlight in the morning helps you sleep better at night.
Certain groups are at higher risk of vitamin D deficiency, such as people with little sun exposure, those with darker skin, older adults, and those with certain chronic diseases. These groups are also at higher risk of depression, making it difficult to understand the relationship between vitamin D levels and mood.
Few foods naturally contain vitamin D. These include oily fish such as trout, salmon, tuna and mackerel, as well as fish liver oils, which are the main sources of vitamin D3, the most bioavailable form of vitamin D. Beef liver, egg yolks and cheese contain small amounts of vitamin D3. Mushrooms provide some vitamin D, but in the form of vitamin D2, which is much less absorbed.
The relationship between vitamin D and mood is complex. It can be one of the determining factors, especially in cases of deficiency, but it can also be a symptom of the disorder rather than a cause. For example, people with depression tend to spend more time indoors and less time outdoors, which would influence their vitamin D levels.
Yet there is evidence to suggest that certain things that produce vitamin D in our bodies, such as certain foods or exposure to sunlight, improve our mood. If winter has left us feeling down, summer can be an opportunity to get our bodies moving again.
Darío Pescador is editor and director of the Quo Magazine and author of the book the best of yourself Published by Oberon.
