Small semi-circular white spots may be found on the fingernails or toenails.
These spots — called “leukonychia” — are a common occurrence, especially in children. More often than not, they simply are a sign of mild trauma to the nail. They may result from some past injury — like getting banged, stuck in a door or exercising in poorly fitting shoes — to the matrix (base) of the nail. The matrix is the part under the visi ble nail where the nail cells and the nail itself are produced. By the time the spots show up (about six weeks after the injury), you would have probably forgotten all about it.
According to some doctors, the appearance of the spots could also mean you have zinc deficiency. Others believe they are an indicator of calcium deficiency.
Whatever the cause, they are temporary and will grow out as your nails grow. Never try to buff them off as this can lead to brittle nails. There’s no way to erase the spots.