Something most do not think about is " coconut" either the water/mild/pulp is the best way of hydration AND can be used as an I.V. to hydrate directly into the body.
Natural ways of hydration are easy on the body's immune system..lemon water cleanses the kidney and removes toxins..dark berries and fruits help to detox ..
Olives/Almonds..Cabbage, Carrot juice..added to your regular diet also help keep skin toned and help digestion which plays a big part in whether you have healthy looking skin..and ice water before eating food helps to digest food easier...
Vitamins K,C,D, B1, E, in natural form or natural supplements..