Tiny white spots on your fingernails may be more than just a cosmetic issue. Dr. Shirley Koeh explains that leukonychia could signal health problems like zinc, selenium, or protein deficiencies, and even arsenic exposure from contaminated rice. Nails reflect underlying health, with persistent white spots possibly indicating leukonychia. Nutrient deficiencies such as zinc, selenium, or protein can weaken nails and cause these spots.