The skin, as contact area to the outside world, is put under particular strain. Not least for this reason it is subject to a rapid renewal process, which requires an intensive metabolism and the provision of building materials. Therefore, the body needs a sufficient supply of nutrients, such as vitamins, to optimize skin texture.

Vitamin deficiency often leads to changes in the skin. These deficiency symptoms disappear when the supply of nutrients is optimized. Thus, normal skin texture as well as the growth and the appearance of nails and hair are diet-dependent.