Of uncertain origin. If not simply an invention, it may have been devised as a feminine equivalent of Alan (of which it is an anagram), or a shortened form of Alana. It seems to have been first used by the American film actress Lana Turner (1920–1995), whose original name was Julia.
Spanish: 1. habitational name from any of numerous places named Soto or El Soto, from soto ‘grove’, ‘small wood’ (Latin saltus). 2. Castilianized spelling of Asturian-Leonese Sotu, a habitational name from a town so named in Asturies. 3. Castilianized spelling of the Galician equivalent, Souto.