PABA is the abbreviation for para-aminobenzoic acid, an organic carboxylic acid. It is a building block of folate and was originally known as vitamin B10 while it was assigned to the Vitamin B group. Today, PABA is no longer considered an essential nutrient (vitamin), as in ideal conditions it is synthesised by the body. PABA is now often referred to as a vitaminoid, or a conditionally essential nutrient.
Bacteria, plants and fungi require p-aminobenzoic acid to synthesise folate. In the human organism, PABA is concentrated in skin cells and in the intestine.