encyclopedia

PABA

Natural Sources:
Brewer’s yeast; wheat germ; whole grains such as rice; eggs; liver; and molasses. PABA is also synthesized by the natural bacteria microflora of our intestines.

Forms:
Standardized PABA supplements including multi-vitamin and mineral products, capsules and tablets.

Therapeutic Uses:
– Aging Disorders

– Blood Health

– Depression

– Digestive Disorders

– Fatigue

– Graying of Hair (premature)

– Hair Health Maintenance

– Headache

– Irritability

– Nervousness

– Premature Graying of Hair

– Skin Cancer Prevention

– Skin Disorders

– Sunburn Prevention

– Sunscreen

– Vitamin (Folic Acid) Deficiency

– Vitiligo (Skin Depigmentation)

– Wrinkles

Overview:
PABA (Para-aminobenzoic Acid) is a member of the water-soluble B vitamins, and also makes up part of the folic acid molecule, another B complex vitamin. PABA is known specifically for its nourishment of hair and its usefulness as a sunscreen. PABA itself is readily available in food and is made by our intestinal bacteria and also supports folic acid production by the intestinal bacteria. As a precursor of folic acid, it supports all of the functions of folic acid within the body and therefore helps to fight aging, mental deterioration, heart disease and cancer. PABA, as a part of the coenzyme tetrahydrofolic acid, also aids in the metabolism and utilization of amino acids and is supportive of blood cells, particularly red blood cells. PABA is important to skin health, hair and skin pigment and intestinal health. Used externally as a sunscreen, it can also protect against the development of sunburn and skin cancer from excess ultraviolet light exposure. PABA deficiency is rare. It is most often caused by the use of sulfa or other antibiotics that destroy beneficial intestinal microflora that produce PABA. Symptoms of PABA deficiency include general fatigue, irritability, depression, nervousness, graying of hair, headache, constipation and other digestive symptoms. Although PABA has been used in attempts to stimulate hair regrowth and to turn gray hair back to its natural color, it has not met with great success. However, it may work in some cases that are related to a PABA deficiency. PABA is also used to reduce aging of the skin and lessen wrinkles. Vitiligo, a skin depigmenting condition, which could result from deficient hydrochloric acid, vitamin C, or pantothenic acid, may be helped somewhat by PABA, both orally and as a cream. PABA ointment is commonly used to prevent and treat sunburns and treat other burns.

Chemistry:
PABA (Para-aminobenzoic Acid) is a member of the water-soluble B vitamins, and also makes up part of the folic acid molecule, another B complex vitamin. Bacteria use p-aminobenzoic acid (PABA) to synthesize folic acid. Folic acid is used as a one-carbon building block in a variety of metabolic pathways, such as nucleic acid synthesis. If the cell does not have folic acid, it cannot synthesize DNA, and the bacteria cannot reproduce. Sulfa drugs mimic PABA because they have many structural features in common. Some of these structural similarities are listed below. PABA is a primary aryl amine with a para-disubstituted benzene ring. PABA has a flat, oblong shape, like a single egg, sunny-side up. [Reference: UCLA Chemistry Tutorial (Summer 1999): Chemistry 140: Organic Reactions].

Suggested Amount:
There is no Recommended Dietary Allowance (RDA) for PABA. Supplements generally contain between 50-1,000 mg. A therapeutic approach used by some practitioners to attempt to restore normal hair color is 1,000 mg., time-released, daily for six days a week, taken with 400 mcg of folic acid. The common treatment amount is usually about 50-100 mg taken three times daily. The use of antibiotics may increase the need for PABA supplements, although PABA taken with sulfa antibiotics may reduce their effectiveness.

Drug Interactions:
PABA taken with sulfa antibiotics may reduce their effectiveness.

Contraindications:
Folic acid supplements (and hence PABA supplements) may be harmful for people who have advanced cancer, are taking drugs for epilepsy, or are vitamin B-12 deficient.

Side Effects:
PABA taken internally in normal dosages generally does not cause any side effects. However, high doses of PABA can cause nausea, vomiting, anorexia, fever, skin rash, liver irritation and vitiligo (skin depigmentation). Some people report being “sensitive” to PABA in vitamin formulations, however, this is thought to be a rare allergic reaction to the para-amino-benzoic acid molecule. PABA used in sunscreens has been reported to potentially (in principle) cause photodegradation to reactive molecules and/or energy transfer to DNA and therefore some people recommend caution with it’s use externally.

Further to this caution, octyl-dimethyl-PABA (OD-PABA) was tested along with other sunscreens for estrogenicity and was shown to cause cellular proliferation and endocrine disruptive activity. These findings are of concern in view of possible long-term effects in humans and wildlife. Recent studies also indicate that UV sunscreen use does not reduce the risk of skin cancer, only the incidence of sunburn. [Gocke E. 2001. Photochemical mutagenesis: examples and toxicological relevance. J Environ Pathol Toxicol Oncol. 2001; 20(4): 285-92. Review; Schlumpf M, Cotton B, Conscience M, Haller V, Steinmann B, Lichtensteiger W. 2001. In vitro and in vivo estrogenicity of UV screens. Environ Health Perspect. 2001 Mar; 109(3): 239-44].

References:

Budde J, Tronnier H, Rahlfs VW, Frei-Kleiner S. 1993. [Systemic therapy of diffuse effluvium and hair structure damage]. Hautarzt 1993 Jun; 44(6): 380-4. [Article in German].

Haas, E.M. 1992. Staying Healthy with Nutrition: The Complete Guide to Diet and Nutritional Medicine. Published by Celestial Arts, Berkeley, CA. Pp. 1168.

Hughes CG. 1983. Oral PABA and vitiligo. J Am Acad Dermatol. 1983 Nov; 9(5): 770.

Khosraviani K, Weir HP, Hamilton P, Moorehead J, Williamson K. 2002. Effect of folate supplementation on mucosal cell proliferation in high-risk patients for colon cancer.

Gut. 2002 Aug; 51(2): 195-9.

Wilson ML, Murphy PA. 2001. Herbal and dietary therapies for primary and secondary dysmenorrhoea. Cochrane Database Syst Rev. 2001; (3): CD002124. Review.

Additional Information:

Positive Results for Treating Hair Problems:

Abstract from Medline: A controlled randomized double-blind study was carried out in 72 female patients to compare tolerance and efficacy of two therapeutic agents containing vitamins of the B-group and L-cystine in different compositions versus a placebo in diffuse effluvia and hair structure lesions. Hair swelling as a criterion of hair quality and frontal and parietal anagen rates in trichograms as criteria of hair growth were determined before and after 4 months of therapy. Treatment with active medication 1 was statistically significantly superior to treatment with the placebo according to these criteria. Treatment with active medication 2 was superior to treatment with the placebo but inferior to treatment with active medication 1. The overall evaluation of efficacy by investigator and patient was in good agreement with these results. The additional active ingredients contained in active medication 1 but not contained in active medication 2 contribute to the efficacy of the medication. They cannot be compensated by the higher amounts of L-cystine contained in active medication 2. Given their good tolerance, no adverse effects were observed with the two active medications. [Budde J, Tronnier H, Rahlfs VW, Frei-Kleiner S. 1993. [Systemic therapy of diffuse effluvium and hair structure damage]. Hautarzt 1993 Jun; 44(6): 380-4. [Article in German]].