Vitamin D is particularly important for bones. Normally, the body can produce it on its own with the help of exposure to the sun. But the sun is often missing in winter. What causes vitamin D deficiency and what can be done about it? An overview.
What is vitamin D and why is it important?
Vitamin D is the umbrella term for a group of fat-soluble vitamins. Unlike other vitamins, it can be synthesized by the body itself by exposing the skin to the sun. The UVB radiation contained in sunlight stimulates the formation of vitamin D.
The body’s own production covers most of the vitamin D requirement. As a rule, 80 to 90 percent are formed with the help of sunlight itself. The rest can be ingested through food.
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Vitamin D plays a central role in bone metabolism. It promotes the absorption of calcium and phosphates from the intestine and their incorporation into the bones. The two minerals are important for hardening the bones. Vitamin D is also involved in other metabolic processes in the body. It also affects muscle strength.
How does a vitamin D deficiency come about?
In the winter months, the intensity and duration of solar radiation in Germany is not sufficient to form vitamin D in the body. The body’s own formation in the sun is only possible from April to October. In spring and summer, vitamin D reserves can be stored in fat and muscle tissue, which the body can fall back on in the dark season.
However, unfavorable climatic conditions, such as heavy cloud cover, can prevent the build-up of sufficient stores, resulting in a low vitamin D level.
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Which risk groups are there?
Certain groups of people have an increased risk of vitamin D deficiency. These include people who are not often outdoors and people with a dark skin color, as they can produce less vitamin D due to the high level of melanin.
Vitamin D production in the body decreases significantly with age. The risk of vitamin D deficiency for older people is significantly higher.
Since infants absorb little vitamin D through breast milk and should not be exposed to direct sunlight, they are also part of the risk group.
What are the symptoms of a vitamin D deficiency?
If the body lacks vitamin D for a long period of time, decalcification and eventually softening of the bones occurs.
The following symptoms can occur:
- bone pain
- Deformations of the bones (especially the ribs, legs and spine)
- muscle weakness
- decreased muscle strength
- broken bones
- Swelling at the junction of cartilage and bone
- softening of the occiput
- susceptibility to infections
- delayed closure of the fontanel in young children
The best way to diagnose a vitamin D deficiency is through a blood test by your doctor. This is recommended if there is reasonable suspicion of a deficiency situation and for persons at risk.
What are the consequences of a vitamin D deficiency?
Without vitamin D, the body cannot absorb enough calcium from food. In adults, this can lead to osteomalacia (softening of the bones) or osteoporosis (bone loss), which occurs primarily in older people.
In infancy and childhood, the bones cannot be adequately mineralized without enough vitamin D. Rickets occurs. Bone growth is disturbed and the skeleton can suffer permanent deformations.
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How can I counteract a vitamin D deficiency?
The German Society for Nutrition recommends spending five to 25 minutes in the sun every day. Especially in spring and summer, this can ensure a sufficient supply of vitamin D for the darker seasons.
Exercise in the fresh air and sport are also good in winter. This strengthens muscles and bones.
The Federal Office for Radiation Protection does not recommend going to the solarium as an alternative in winter, as there are different levels of radiation than in the sun. Solariums also increase the risk of developing skin cancer.
Which foods contain a lot of vitamin D?
Certain foods can cover a small part of the vitamin D requirement.
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Foods high in vitamin D:
- fatty sea fish (herring, salmon, mackerel)
- offal (liver, kidneys)
- Edible mushrooms (chanterelles, button mushrooms)
- Owner
- Dairy products
Can I take tablets for a vitamin D deficiency?
Before vitamin D preparations are taken, it should be discussed with a doctor whether the deficiency can be compensated for through diet or the body’s own vitamin D formation through exposure to the sun.
Symptoms of prolonged overdose
A chronic overdose causes the calcium level in the blood to rise and this has other consequences. This can lead to cardiac arrhythmia and kidney damage. However, too much vitamin D can also cause headaches, vomiting, drowsiness, diarrhea and excessive urination.
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The side effects only occur with long-term consumption of more than 100 micrograms per day, not with too much sun.
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On the subject
This topic in the program:The First | BRISANT | February 07, 2022 | 5:15 p.m