Leukonychia (or leuconychia), also known as white or milk spots on the nails, is a medical term for white discolorations that often occur on nails. The term is derived from the Greek words leuko (“white”) and onyx (“nail”). The most common cause for them to appear is an injury to the base of the nail (the matrix) where the nail is formed.
Despite the popular belief, milky spots on fingernails are not a sign of deficiency or excess of calcium or zinc, or other vitamins, as many cultures believe. The deficiencies most commonly linked to white nails are zinc and calcium deficiency, but the spots are actually completely harmless and can occur in anyone, including babies and elderly people.
Fungal disease or infection of the nail or skin around the nail can be the cause of white spots on the nails. Essential oils have been said to “cure” white spots caused by injuries to the nail, or nail fungus, but there’s no actual scientific proof to validate this claim.