The majority of white spots on fingernails are caused by a previous injury to the nail bed. In most cases, when white spots appear on a single or a couple of fingers or toes, the most common cause is injury to the base (matrix) of the nail. When this is the case, white spots disappear after around eight weeks, which is the amount of time necessary for nails to regrow completely. White spots showing up on all or nearly all nails for longer periods of time (months or years) can be due to one of several reasons; one of which is zinc deficiency.
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