Vitamin B10 (pABA (para-AminoBenzoic Acid)) - Essential Background Reading
Essential Background Reading
Vitamin B10, also known as factor R was later determined to be pteroylmonoglutamic acid mixed with other B vitamins. Its deficiency caused slowed growth and deteriorated feather development in chicks, along with blood problems. It was believed by some researchers to apply to humans. Some early researchers used the term "vitamin B10" to denote para-aminobenzoic acid.
para-aminobenzoic acid (pABA), a component of pteroylglutamate, was once considered a vitamin and named vitamin B-x because it serves as a provitamin for some bacteria. Later studies in humans demonstrated that it does not have vitamin activity because humans lack the ability to synthesize folate from pABA. This biochemical is very useful in other ways and has been extensively utilized as a sunscreen in topical lotions to protect the skin from harmful ultraviolet radiation upon exposure to the sun. It is also effective in the treatment of vitiligo, a condition that causes discoloration of the skin. Natural sources of pABA include bran, kidney, liver, molasses, wheat germ, and yogurt. There are no reported symptoms arising from a dietary deficiency of pABA.
principal proposed Treatments
There are no well-documented uses for pABA
Other proposed Uses
Scleroderma, peyronie's Disease, Male Infertility, Vitiligo
para-aminobenzoic acid (pABA) is best known as the active ingredient in sunblock. This use of pABA is not really medicinal: like a pair of sunglasses, pABA physically blocks ultraviolet rays when it is applied to the skin.
There are, however, some proposed medicinal uses of oral pABA supplements. pABA is sometimes suggested as a treatment for various diseases of the skin and connective tissue, as well as for male infertility. However, most of the clinical data on pABA comes from very old studies, some from the early 1940s.
pABA is not believed to be an essential nutrient. Nonetheless, it is found in foods, mainly in grains and meat. Small amounts of pABA are usually present in B vitamin supplements as well as in some multiple vitamins.
A typical therapeutic dosage of pABA is 300 to 400 mg daily. Some studies have used much higher dosages. However, serious side effects have been found in dosages above 8 g daily (see Safety Issues). You probably shouldn't take more than 400 mg daily except on medical advice.
pABA has been suggested as a treatment for scleroderma, a disease that creates fibrous tissue in the skin and internal organs.1,2 However, a small double-blind study found it ineffective.3
pABA has also been suggested for other diseases in which abnormal fibrous tissue is involved, such as peyronie's disease, a condition in which the penis becomes bent owing to the accumulation of such tissue.4,5,6 However, no double-blind studies have yet been performed.
Based on one small World War IIera study, pABA has been suggested for treating male infertility as well as vitiligo, a condition in which patches of skin lose their pigment, resulting in pale blotches. However, this study didn't have a control group, so its results aren't meaningful.7 Ironically, a recent study suggests that high dosages of pABA can cause vitiligo (see Safety Issues).
pABA is probably safe when taken at a dosage up to 400 mg daily. possible side effects at this dosage are minor, including skin rash and loss of appetite.8
Higher doses are a different story, however. There has been one reported case of severe liver toxicity in a woman taking 12 g daily of pABA.9 Fortunately, her liver recovered completely after she discontinued her use of this supplement. Also, a recent study suggests that 8 g daily of pABA can cause vitiligo, the patchy skin disease described previously.10
Clearly, there are questions that need to be answered about the safety of high-dose pABA therapy. You shouldn't take more than 400 mg daily except under medical supervision.
pABA may interfere with certain medications, including sulfa antibiotics.11,12
Safety in young children, pregnant or nursing women, or those with serious liver or kidney disease has not been determined.
Interactions You Should Know About
If you are taking sulfa antibiotics such as Bactrim or Septra, do not take pABA supplements except on medical advice.
- Zarafonetis CJ, Dabich L, Skovronski JJ, et al. Retrospective studies in scleroderma: skin response to potassium para-aminobenzoate therapy. Clin Exp Rheumatol. 1988;6:261268.
- Zarafonetis CJ, Dabich L, Negri D, et al. Retrospective studies in scleroderma: effect of potassium para-aminobenzoate on survival. J Clin Epidemiol. 1988;41:193205.
- Clegg DO, Reading JC, Mayes MD. Comparison of aminobenzoate potassium and placebo in the treatment of scleroderma. J Rheumatol. 1994;21:105110.
- Hasche-Klunder R. Treatment of peyronie's disease with para-aminobenzoacidic potassium in German; English abstract. Urologe A. 1978;17:224247.
- Carson CC. potassium para-aminobenzoate for the treatment of peyronie's disease: is it effective Tech Urol. 1997;3:135139.
- Ludwig G. Evaluation of conservative therapeutic approaches to peyronie's disease (fibrotic induration of the penis). Urol Int. 1991;47:236239.
- Sieve BF. The clinical effects of a new B complex factor, para-aminobenzoic acid, on pigmentation and fertility. South Med Surg. 1942;104:135139.
- physicians' Desk Reference. Oradell, NJ: Medical Economics Co; 1989.
- Kantor GR, Ratz JL. Liver toxicity from potassium para-aminobenzoate. J Am Acad Dermatol. 1985;13:671672.
- Hughes CG. Oral pABA and vitiligo letter. J Am Acad Dermatol. 1983;9:770.
- Degowin RL, Eppes RB, Carson pE, et al. The effects of diaphenylsulfone (DDS) against chloroquine-resistant plasmodium falciparum. Bull World Health Organ. 1966;34:671681.
- Vinnicombe HG, Derrick Jp. Dihydropteroate synthase from Streptococcus pneumoniae: characterization of substrate binding order and sulfonamide inhibition. Biochem Biophys Res Commun. 1999;258:752757.