Strictly speaking, vitamin D is a hormone that the body produces itself in the skin under the influence of UV-B radiation. The storage form 25-OH-vitamin D3 is measured because it reliably reflects vitamin D status over several weeks. Vitamin D regulates the absorption of calcium from the intestine and also affects the muscles and immune system.
Por que este valor é medido?
In Germany, sunlight from October to March is insufficient to produce enough vitamin D. Deficiencies are therefore widespread and usually go unnoticed because the symptoms – fatigue, muscle weakness, and susceptibility to infections – are nonspecific.
Valor alto
Very high levels practically only result from overdosed supplements and can cause harm through an elevated calcium level. Overdosing from sunlight alone is not possible.
Valor baixo
Low levels promote bone loss, muscle weakness, and susceptibility to infections. At-risk groups include older people, people with dark skin, shift workers, and anyone who spends little time outdoors.
Perguntas frequentes
When should the vitamin D level be measured?
The most informative time to measure it is at the end of winter, in February or March, when stores are at their lowest.
How long does it take for the level to improve?
With regular intake, the level rises over approximately eight to twelve weeks. A follow-up measurement is advisable no earlier than three months later.
Is sunlight enough in summer?
For people with light skin, 10 to 20 minutes of midday sun on the face and forearms is often enough in summer. In winter, the sun is too low in Germany for significant natural production.
