PABA by Ray Sahelian, M.D.

Para-aminobenzoic acid or PABA is a non-protein amino acid sometimes referred to as a vitamin, but PABA is neither a vitamin nor an essential nutrient for humans. PABA is an intermediate in the synthesis of folic acid in bacteria. The sulfonamide antibiotics are structurally similar to PABA and interfere with the synthesis of nucleic acids in sensitive micro-organisms by blocking the conversion of PABA to the co-enzyme dihydrofolic acid, a reduced form of folic acid. In humans, dihydrofolic acid is obtained from dietary folic acid; thus sulfonamides do not affect human cells. PABA is also known as 4-aminobenzoic acid.

PABA is a compound that is an essential nutrient for microorganisms and some animals, but has not been shown to be essential for people. PABA is considered by some to be a member of the vitamin B-complex, though its actions differ widely from other B vitamins. The most well-known property of PABA is as an effective sunscreen, when used topically. Oral PABA supplementation has not been shown to possess any sunscreening properties.

PABA in Food
PABA is found in liver, brewer’s yeast, wheat germ, whole grains, and eggs. PABA is also synthesized by the natural bacteria flora in the intestines.

PABA supplement
You can find PABA in a dose of 500 mg or 1000 mg, and PABA is often found in multivitamin supplements. Click here if you would like to learn or purchase a very popular multivitamin supplement that I have formulated called MultiVit-Rx.

PABA sunscreen
Use a PABA free sunscreen if you are allergic to PABA. Those who are allergic to PABA can get an itchy rash.

PABA and Hair
PABA has been promoted for hair growth or to restore hair loss, or to restore hair color. There is not evidence at this time that a PABA supplement or a PABA hair product will restore hair loss or hair color, unless perhaps if someone has a severe deficiency of PABA, which would be quite rare.

PABA Research
Para-aminobenzoic acid (PABA) used as a marker for completeness of 24 hour urine: effects of age and dosage scheduling.
Eur J Clin Nutr. 2003 Jan;57(1):138-42.
To examine the age dependency of the urinary para-aminobenzoic acid (PABA) excretion, and if a delayed PABA excretion can be overcome by advancing intake schedule; and to examine the recovery of PABA in fractionated urinary samples collected during 24 h after single and repeated doses of PABA. CONCLUSION: There is a gradual decline of PABA recovery with age that cannot be overcome by advancing the dosage schedule. Because of a lower delimiting PABA recovery for the elderly, some 24 h collections in this age group will be rejected unjustly (false-negatives). Also, with the currently recommended dosage schedule (PABA taken with the main meals) the risk of false-positive 24 h urine collections prevails. With refinement of the PABA test procedure, ie employing a specific analytical method and age-dependent cut-off values, the test may achieve a higher specificity and sensitivity.

PABA emails
Q. Is PABA a vitamin? I heard that PABA also comes as an injection.
   A. Although many people believe PABA to be one of the B vitamins, technically it is not a vitamin or an essential nutrient since the body can make it. I am not familiar with the injectable form of PABA.