Hi, One of the most common cause for these little white spots, which can show up on both fingernails and toenails is called Leukonychia . But many peoples are think they are caused by calcium or zinc deficiency. In reality, these spots most often develop as result of mild to moderate trauma to your nail. Another possibility is that the spots could be a sign of a mild infection or allergy. But these spots typically do not require any treatment and should go away as your nail grows out and should not return unless you affected. The Leukonychia could be related to another more serious condition is anemia. So that, eat rich foods and maintain personal hygine.