Sano is the "healing" aspect, composed of Victus and Ordo (before 4.2.2, it was Victus+Victus). It has no compounds. It is used in a few key recipes, notably the Ethereal Bloom and (later) Sanitizing Salts. It is quite scarce in items, but is found in Three Meat Treat, and in Healing or Regeneration potions. (It is also present in milk, but that's useful only for scanning, unless you can afford to sacrifice many buckets.)
Until recently (before 18.104.22.168) it was also available from cake, since cake is crafted from milk. This was removed when Azanor modified the algorithm for computing the aspects of crafted items -- the new system gave cake an unreasonable amount of Metallum, so cake was redefined with more typical "food" aspects.