How do you know if you have a zinc deficiency?

See below: Symptoms include: growth failure, primary hypogonadism, skin disease, impaired taste and smell, and impaired immunity and resistance to infection. However, any of these symptoms are much more likely due to more mundane causes rather than zinc deficiency unless you eat a protein poor diet in the third world or you are a lacto-ovo-vegetarian.

White spots on nails: Leukonychia = white spots on the finger nails and is a very reliable indicator of suboptimal zinc levels. Suboptimal zinc levels are exceedingly common because stress causes increased zinc loss and zinc intake has declined with decreased whole food, non-organic diets. Mental lethargy, poor memory, poor growth, decreased immune function and skin conditions are other symptoms of zinc problems.