What do white spots on finger nails mean?

Damage or fungus: It depends on where the white spots are. It could represent damage to the nail matrix several months ago at the base of the fingernail or could be a fungal infection if the white spot is out on the tip and somewhat irregular.

Injury,fungi,lo zinc: There can be many causes but the most common are injury, nail fungus and zinc deficiency. See http://www.Md-health.Com/white-spots-on-nails.Html ; http://drlwilson.Com/articles/zinc.Htm.