PABA is an acronym for para-aminobenzoic acid. It is a pseudo-vitamin, loosely classified as a member of the B-vitamin complex. It has no known nutritional value for humans; therefore, there is no daily requirement recommendation. Likewise, there are no known deficiency symptoms. PABA's most documented and effective health application is its ability to protect the skin from the sun's UV rays. It is the active ingredient used in most sunscreen products. The reason for its effectiveness as a sun block is not known.
PABA is found in liver, kidney, whole grains, and molasses.
Large doses of PABA are associated with side effects such as malaise, liver disease, fever, and low white blood cell counts. No serious side effects have been reported with doses as high as 300–400 mg per day. PABA is frequently found in small doses in B-complex vitamins and multi-vitamin formulas.