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Vitamin PABA
Description:
PABA (Para-aminobenzoic acid) is classified as a vitamin-like substance. In its para-aminobenzoil moiety it is a factor in the vitamin B-complex vitamins and a component of folacin. Bacteria are able to synthesize folic acid from PABA; therefore, for these organisms, it is considered a vitamin. Humans, however, cannot use aminobenzoic acid to synthesize folacin. PABA does perform certain metabolic functions in some animals.
Method of Action:
PABA is a component of many biological systems and participates in many metabolic processes. It appears to function as a coenzyme in the conversion of certain chemical intermediates to purines. It has also been suggested that PABA has an antifibrosis activity, increasing oxygen uptake at the tissues. This increase in oxygen may enhance monoamine oxidase activity; furthermore, it is believed that too little monoamine oxidase activity is a contributing factor to fibrosis. These effects are, at present, still considered speculative.
PABA has no nutritional value for humans.
It has been reported that folacin and vitamin C assist the absorption of PABA; ethanol, coffee, sulfa drugs, and cola drinks prevent absorption.
Properties & Uses:
PABA is used as a topical sunscreen, absorbing ultraviolet light of wave lengths between 190 and 270 nanometers. However, it does not absorb in the near ultraviolet range, 350 to 400 nanometers, and therefore does not prevent drug-related photosensitivity and phototoxicity.
PABA is also used in combination with salicylates in the treatment of rheumatic fever.
Toxicity Levels:
There is no toxicity related to PABA.
Recommended Dietary Allowances:
RDA for adults: 400 mcg
RDA for children 200 - 300 mcg
RDA for infants 50 mcg
RDA for pregnancy 800 mcg
RDA for lactation 600 mcg
Food Sources:
· Beef liver
· Bran flakes
· Brewer's yeast
· Chicken liver
· Egg (whole)
· Lamb liver
· Molasses
· Rice
· Turkey liver
· Veal liver
· Wheat germ
· Whole wheat
Deficiency Symptoms:
Deficiencies of PABA have not been described in humans, and most nutritionists do not consider it an essential nutrient.
Side Effects & Interactions:
No serious side effects have been reported with 300–400 mg per day. Larger amounts (such as 8 grams per day or more) may cause low blood sugar, rash, fever, and (on rare occasions) liver damage.1 One report exists of vitiligo appearing after ingestion of large amounts of PABA2 and use of amounts over 20 grams per day in small children has resulted in deaths.3 There is also a report of a death from toxic hepatitis in a person with lupus, who took as much as 48 grams per day for six days, followed by 8 grams per day for seven months.4
No interactions between PABA and other nutrients have been reported. However, PABA interferes with sulfa drugs (a class of antibiotics) and therefore should not be taken when these medications are being used.