I think that it is water but I can't be sure. We just learned this in science so I might know. If I find out I will post it.
Water
Salt
Salt
Water
alveoli
calcium
The lungs of course
Gastric juice.
Yes. Iodine is a necessary nutrient.
vitamin D
Infants have the highest protein needs relative to body weight of any time of life.
the dead sea is the saltiest body of water in the world.
vitamin D
Vitamin D?
In regards to body of water, the highest amount on salinity can be found in Lake Don Juan in Antarctica.