Since 70 years vitamin D is used to prevent rachitis. Studies during last years show now that vitamin D has eminent effects for the whole human body, not only for bones. Every other in Germany is undernourished regarding vitamin D. Too less food rich in vitamin D, as for instance liver or fish, is part of our daily food. 
Our body produces vitamin D with the sun’s assistance (UV radiation). So we call it also the „sunvitamin“.  Results in human beings show that our kind of living may not be able to keep a higher level of vitamin D in our blood plasma.
During winter times the sun is only low, we cannot produce sufficiently vitamin D through the skin. The elderly skin is also unable even in summertime to produce as much as younger skin does. Many teenagers and children already have low vitamin D levels due to their kind of living. Vitamin D supplied by the daily food or produced under assistance of the skin is converted into the active vitamin D in liver and kidneys; now we call it hormone D.

Sufficient supply of vitamin D is important for the body as nearly all functions of body’s organs, muscles and tissues depend on a good vitamin D level. To maintain

• a normal function of the immune system and healthy reaction on inflammation 
• a normal muscle function 
• a healthy growth and healthy development of children 
• cell protection and prevention of Free Radicals