PABA supplement information and benefit
December 20 2017 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 and dietary sources
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 over the counter
You can find PABA in a dose of 500 mg or 1000 mg, and PABA is often found in multivitamin supplements.

PABA sunscreen
Use a PABA free sunscreen if you are allergic to it. Those who are allergic to it can get an itchy rash. Some organic UV filters (PABA derivatives, cinnamates, benzophenones, and octocrylene) have been described to cause photoallergy.

PABA and Hair growth or color
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 such a hair product will restore hair loss or hair color, unless perhaps if someone has a severe deficiency of PABA, which would be quite rare.

Hello. I am a girl and 25. I have seen two grey (single) hair recently and consult a doctor. He prescribed PABA (oral). Would you please tell me about eventual detriments of this supplement ? (e.g. I have heard it reduces quantity of white corpuscle of blood) Can it help me preventing my hair being grey?
   A. At this time we are not aware of PABA being effective for restoring grey hair. I am not aware of studies evaluating long term side effects of this vitamin.

Interactions with medications
Q.  I am interested in supplementing PABA. I currently take Bactrim for acne and have been long term. I am concerned with the inhibition and the possibility of deficiency or PABA and folate as a result. What may be the issues with taking PABA and Bactrim at the same time? Will it just inhibit the vitamin making it ineffective?
   A. I have not seen studies regarding this combination, therefore it is not easy to know what kind of interactions, if any, there would be.

Para-aminobenzoic acid used as a marker for completeness of 24 hour urine: effects of age and dosage scheduling.
Eur J Clin Nutrition. 2003.
To examine the age dependency of the urinary para-aminobenzoic acid excretion, and if a delayed PABA excretion can be overcome by advancing intake schedule; and to examine the recovery in fractionated urinary samples collected during 24 h after single and repeated doses of PABA. 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.

J Acad Nutr Diet. 201. Effects of Para-Aminobenzoic Acid (PABA) Form and Administration Mode on PABA Recovery in 24-Hour Urine Collections. Our aim was to investigate the effect of form (PABA vs aminobenzoate potassium) and administration mode (directly ingested as a tablet/capsule vs added to food) on urinary PABA recovery levels. Twenty healthy participants underwent 3 test days separated by two 24-hour wash-out periods. Three test conditions, one on each test day, were investigated in randomized order: PABA tablet, aminobenzoate potassium capsule, and PABA or aminobenzoate potassium in food. Ingestion of each dose was supervised and participants performed the 24-hour urine collections while free-living. The 24-hour urine collections were analyzed for PABA recovery (%R) levels using a colorimetric assay. Recoveries 85% to 110% were deemed complete and those >110% were reanalyzed by high pressure liquid chromatography and mass spectrometry. These results suggest that aminobenzoate potassium may be used as an alternative to PABA for assessing the completeness of 24-hour urine collections and to track compliance with consuming provided diets in community-dwelling studies.

Q. Is PABA a vitamin? I heard that PABA also comes as an injection.
   A. Although many people believe it 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.

Q. I took some Para-aminobenzoic acid 500mg for to improve white patches on my skin. I have secondary adrenal insufficiency from lack of ACTH stim test according to endocrinologist. I am presently taking Levothroid and Cytomel for Hashimoto's thyroiditis and have Sjogrens syndrome. (two autoimmune diseases) and rheumatologist thinks i may either have lupus or mixed connective tissue disease. I am presently on 30mg of hydrocortisone daily for another two months then we will try to taper off. I am taking vitamin C, panthothenitc acid too! I started the paba because I also read that is heals adrenals too. But it gave me terrible headaches and my body ached all over. Another doctor i went to said I might have system yeast and paba comes from yeast form. I do get chronic yeast infections and sinus yeast infections because I have to take amphoterecin B nasal spray instead of antibiotic. Why does Paba cause body aches and headaches? is it really the systemic yeast?
   A. High dosages of certain supplements can cause side effects, and there are unexpected side effects when supplements and medications are combined. Sometimes lowering the dosage can reduce these unpleasant side effects.