Tin binds water about as tightly as sulfides (sulfur or S--), so water may provide some protection from tin when in its lower oxidation states. The problem is that it may oxidize In atmospheric oxygen and when heated as in solders. Nutritional requirements for nickel are not easily determined and it is more likely to be pervasive and toxic in our current environment. Zinc is one of the least toxic and most nutritious of all the elements. For example, it is used extensively by our bodies in enzymes catalyzing important chemical reactions, like the digestion of protein and the detoxification of alcohol. It is also essential for the stability of insulin needed to detoxify the sugar insults that processed foods typically contain.