When I was in school, I always remember hearing that small white spots on your fingernails appeared because you weren't getting enough calcium and zinc.
Is there any truth to that or it is an old wive's tale?
-- Jessica Climdow
(City withheld), MN
It's an absolute myth.
White spots on fingernails form as a response to injury (i.e.: accidentally slamming your fingernail on a counter top).
It's similar to skin developing a bruise when, for instance, you bump your elbow against something.
Whereas bruises to the skin can show up within a day or two, white spots on fingernails take much longer.
Since nail growth happens so slowly, it can take as much as two or three months for a spot to form -- and vanish!
In rare occasions, these white spots can also appear if you are allergic to a certain type of nail polish.
Sometimes, too, they are caused by bacterial infections underneath the nail. This is easy to spot, though, since usually this sort of infection results in part of the nail developing a greenish tint.
FYI: the classic symptoms of calcium deficiency are muscle cramping and twitching.
If you are deficient in zinc, you would experience significant hair loss, general fatigue, bruising on your skin, and often times, a decrease in appetite.