Properly pretreated (if necessary) and dried, most dehydrated foods keep all of the nutrition, including vitamins, minerals, proteins, and fiber, as their fresh counterparts. They also retain all their calories. Vitamins A & C are lost with high drying temperatures, and some water-soluble vitamins may be lost in blanching. However, blanching helps stop the enzymatic process that makes foods turn color or degrade faster. If you wish to keep all the nutrients in your dried food, dry it below 115°F/46°C.