The subject for a volume on the fat-soluble vitamins needs no justification considering the importance of this group of nutrients and the rate of expan- sion of our knowledge of its role in cell biology, genetics, and disease. The level of our understanding has clearly moved from knowing what fat- soluble vitamins do to how they perform their functions. Hand in hand with a knowledge of their molecular mechanisms of action is the recognition that vitamins are used sparingly, and regeneration processes operate in certain cases to recycle vitamins from their metabolites. We have divided the...

This book will explain the colossal potential of life to cope with different living environments is possible owing to the exceptionally well developed mechanisms of adaptation to environmental conditions. There is an innumerable variety of concrete mechanisms which make it possible for living creatures to adapt to different and changing environmental conditions. Nevertheless, all this variety is the manifestation of the three strategic line of the adaptation process: 1. Evolutional or genotypic adaptation. 2. Phenotypic adaptation. 3. Rapid adaptation.