You’ve likely heard that these spots indicate health issues, such as calcium deficiency. But as Dr. Jessica Krant, a board-certified dermatologist in New York City, tells Huffington Post that’s not true:
“Calcium deficiency causing white spots on nails is the most common myth, followed by zinc deficiency. The truth is that white spots are common and harmless and don’t indicate any specific vitamin deficiency at all.”
Dr. Andrew Weil agrees, explaining the white spots, also known as ‘Leukonychia,’ are most often caused by injuries:
“Most of the time the white spots simply are a sign of some past injury to the matrix (base) of your nails. By the time the white spot shows up (about six weeks after the injury) you’ve probably forgotten all about banging or knocking your fingers. Sometimes, the injury can stem from a manicure that put excessive pressure on the base of the nails.”
Weil also says white fingernails could be due to an allergic reaction you have to a nail polish or a mild infection.