The sunny side of life: vitamin D and its vital benefits

Vitamin D is more than just a vitamin; it is an essential regulator for numerous bodily functions. In contrast to other vitamins, which you have to absorb mainly through food, your body can produce vitamin D itself. This production is stimulated by the effect of sunlight on your skin. The importance of vitamin D for bone health is well known, but it also has significant effects on other aspects of your health, including your skin, hair and psyche.

How is vitamin D produced?

Vitamin D is unique in that your body can produce it itself, an ability that not many vitamins share. This happens in your skin through a process triggered by the sun’s UV-B rays. Here’s how it works:

1. UV-B radiation: When UV-B rays hit the skin, vitamin D3 (cholecalciferol) is synthesised from a chemical present in the skin (7-dehydrocholesterol).
2. Liver and kidneys: The vitamin D3 formed in this way is then transported to the liver, where it is converted into 25-hydroxyvitamin D. This form is the main circulating hormone of vitamin D in the body. It is then converted into its active form, 1,25-dihydroxyvitamin D, in the kidneys.

Your skin’s ability to produce vitamin D can be affected by several factors, including where you live, the time of year, the time of day and, of course, your skin type. For example, darker skin needs longer exposure to sunlight to produce the same amount of vitamin D as lighter skin.

Vitamin D and bone health

Vitamin D plays a crucial role in the health of your bones. It helps your body absorb calcium from your diet, which is essential for building and maintaining strong bones. Here are two key aspects of the relationship between vitamin D and bone health:

The role of vitamin D in bone metabolism

Vitamin D promotes the absorption of calcium and phosphate from the gut, which is necessary for bone mineralisation. Without sufficient vitamin D, your body cannot effectively utilise the calcium you absorb from food, which can lead to softer bone structure, known as osteomalacia in adults and rickets in children.

Vitamin D deficiency and bone diseases

A lack of vitamin D can lead to a decrease in bone quality and density, which increases the risk of osteoporosis and bone fractures. Adequate vitamin D levels are particularly important for older people in order to maintain bone strength and minimise the risk of falling.

Recognising vitamin D deficiency

To recognise a vitamin D deficiency, you should look out for certain signs and symptoms, which could indicate that your vitamin D levels are low.

The most common symptoms include:

• Tiredness and general exhaustion,
• diffuse bone pain or tenderness, which is particularly noticeable in the sternum or tibia, and
• muscle weakness or pain, which occurs for no apparent reason,

Some people also report:

• Mood swings, including
• depressive episodes.

In children, a lack of vitamin D can lead to

• growth retardation or to a
• lead to softening of the bones (rickets).

The safest way to diagnose a vitamin D deficiency is a blood test that measures the level of 25-hydroxyvitamin D, which provides the best assessment of your vitamin D status. If you notice any of these symptoms, it is advisable to see a doctor to have your vitamin D level checked and take appropriate action.

Vitamin D and mental health

There is increasing evidence that vitamin D plays an important role in mental health, particularly in relation to depression. Studies have shown that low vitamin D levels can correlate with a higher risk of depression and the severity of depressive symptoms.

Vitamin D acts on areas of the brain that are important for mood regulation and influences the production of neurotransmitters such as serotonin, which are directly linked to mood and well-being.

A lack of vitamin D could therefore disrupt neurotransmitter synthesis and increase the risk of mood swings and depressive disorders. Although the exact mechanisms require further research, the available data suggest that adequate vitamin D intake should be considered as part of a comprehensive approach to supporting mental health and treating depression.

Influence of vitamin D on general health

Vitamin D is crucial for more than just your bone health; it also plays an important role in various other aspects of health:

Immune system

Vitamin D is an important player in the functioning of your immune system. It helps modulate your immunity by boosting both the innate and adaptive immune response. This can help reduce the risk of infections such as the flu and autoimmune-related diseases. Studies have shown that adequate vitamin D levels are linked to lower rates of respiratory infections and improved immune response.

Prevention of chronic diseases

There is growing evidence that vitamin D also plays a role in the prevention of various chronic conditions such as heart disease, diabetes and certain cancers. Although the exact mechanisms are still being investigated, some studies suggest that vitamin D may help through its anti-inflammatory properties.

Vitamin D and skin health

Vitamin D is not only important internally, but also has a direct effect on skin health:

Protective mechanisms of the skin

The skin is not only the site of vitamin D synthesis, but also benefits directly from its properties. Vitamin D supports skin repair and renewal and plays a role in the skin barrier function, which is important for maintaining moisture and protection against external influences.

Vitamin D and skin diseases

Adequate levels of vitamin D can be helpful in the prevention and treatment of skin conditions such as psoriasis and eczema. Vitamin D regulates the growth and differentiation of skin cells, which means that it can be useful in the treatment of skin conditions characterised by irregular cell formation.

Vitamin D and hair loss

Vitamin D plays an important role in the formation of hair follicles – the tiny pores in the skin from which hair grows. A vitamin D deficiency can lead to hair loss and is associated with conditions such as alopecia areata, an autoimmune disorder which causes significant hair loss. An adequate supply can therefore not only keep your hair healthier, but also contribute to its growth.

Sun protection and vitamin D

There is a widespread myth that sunscreens can completely block vitamin D synthesis. However, this is not the case. We do not even apply enough sunscreen to impair vitamin D synthesis.

The synthesis of vitamin D is not completely prevented by sunscreen, as many people do not apply enough of it. In addition, the protection applied is often uneven and some areas often remain unprotected, such as the scalp and ears. There are also specially developed sun protection creams, which do not affect vitamin D synthesis.

So don’t skimp on sun protection and use at least SPF 30.

Sources of vitamin D

Your body’s ability to effectively synthesise and use vitamin D depends heavily on your exposure to certain sources. Here are the primary sources through which you can optimise your vitamin D levels:

Exposure to sunlight

Sunlight remains the most important natural source of vitamin D. About 5-30 minutes of sun exposure between 10am and 3pm, twice a week (with sunscreen!) on your face, arms, legs or back, can be enough to promote healthy vitamin D production. The exact duration depends on your skin type, your geographical location and the time of year.

The lighter the skin, the shorter the exposure to the sun should be. The more skin is exposed, the shorter the stay in the sun should be.

When using certain skin care ingredients, sun exposure should always take place with sun protection, this is the case with AHAs, BHAs, PHAs and retinol or retinoids.

Supplements can also play an important role, especially for people who do not have regular access to sunlight or who have certain dietary restrictions. Vitamin D supplements are available in various forms such as tablets, drops and capsules.

Vitamin D overdose

An overdose of vitamin D, also known as hypervitaminosis D, can cause serious health problems as vitamin D is fat-soluble and is stored in body fat, which can lead to accumulation in the body if taken in excessive amounts.

The symptoms of a vitamin D overdose include:

• nausea,
• vomiting,
• weakness,

and serious complications such as

• Hypercalcaemia – an excessive concentration of calcium in the blood, which can lead to calcium deposits in the blood vessels and organs. In the long term, this can lead to
• lead to heart and kidney problems.

Most cases of vitamin D overdose are caused by excessive consumption of supplements, as natural overdose from sun exposure or food is very rare. It is therefore important not to exceed the recommended daily dose when taking vitamin D supplements and to have regular blood tests carried out to monitor vitamin D levels in the body.

Conclusion

Vitamin D is a vital vitamin, which plays a key role in the health of your bones, immune system, skin and hair. It is synthesised through sunlight exposure and can also be obtained through food and supplements. It’s important to find a healthy balance between sun protection and sun exposure to meet your vitamin D needs without increasing the risk of skin damage.

Frequently asked questions