Zinc levels in blood, hair and other tissues are indicators which have been inconclusive and sometimes misleading. In the early 1980s a simple taste test was developed and reported in The Lancet. To create a test solution, dissolve 0.1 percent zinc sulfate (available at health some food stores and your locl pharmacy) in a base of distilled water. You should refrain from eating, drinking or smoking for at least an hour before the test, then place about a teaspoon of the solution in your mouth and swish it around for 10 seconds. If it tastes unpleasant or metallic, your level of zinc is probably adequate. However, if the solution tastes like water, you may be receiving less zinc than you need.
Zinc deficiency has been implicated as a factor in: