What is Vitamin B10 (PABA)?
Vitamin B10 is an older, alternative name for para-aminobenzoic acid, or PABA. PABA is a chemical compound found naturally in some foods and produced synthetically for supplements and cosmetics. Unlike true vitamins, which the human body cannot produce on its own, PABA is considered a nonessential nutrient for humans because our gut bacteria can synthesize it. Despite its history as a classified B-vitamin, it is no longer officially recognized as such.
Is PABA an Essential Vitamin?
No, PABA is not an essential vitamin for humans. The defining characteristic of a vitamin is that the body cannot produce it, making it an essential part of the diet. While PABA is an important nutrient for some bacteria and plants, and our gut microbiome utilizes it to produce a small amount of folate (vitamin B9), this amount is insufficient to meet our total needs. Therefore, humans must get the majority of their folate from dietary sources.
Primary Functions of PABA
The primary function of PABA in the human body is its role in the synthesis of folate (vitamin B9). This process is carried out by bacteria in the gut, which use PABA as a precursor molecule.
The Gut-Folate Connection
- Folate Synthesis: Gut bacteria combine PABA with other compounds to create folate.
- DNA Synthesis: The folate produced is necessary for vital bodily functions, including DNA and RNA synthesis and the formation of healthy red blood cells.
- Inadequate Supply: It is crucial to understand that the folate produced by gut bacteria from PABA is not enough to meet human nutritional requirements, so a balanced diet rich in folate-containing foods is still necessary.
Historical and Investigational Uses
Over the years, PABA has been studied and used for several purposes, some of which have fallen out of favor or lack strong scientific support.
Role in Sunscreen
- PABA's ability to absorb ultraviolet (UVB) rays made it a popular ingredient in sunscreens starting in the 1940s.
- However, due to concerns over allergic skin reactions in some individuals, the U.S. Food and Drug Administration (FDA) no longer considers it generally recognized as safe and effective for this use as of 2019.
PABA and Skin Conditions
- Scleroderma: PABA supplements have been investigated for treating scleroderma, an autoimmune disease that causes skin hardening. Older studies showed some potential benefits, but more recent evidence is conflicting, and conclusive data is lacking.
- Peyronie's Disease: For Peyronie's disease, a condition involving fibrous plaque in the penis, some early studies suggested oral PABA could be beneficial. However, more recent research indicates it may not be an effective treatment.
Hair Color and PABA
- Graying Hair: Early research in the 1940s and 1950s explored PABA's potential to reverse premature graying hair. Some participants did experience hair darkening, but the effect was not permanent and reversed after stopping supplementation.
- Modern Evidence: There is a lack of modern scientific research to support PABA supplementation for hair repigmentation.
Dietary Sources of PABA
Though not essential, PABA can be obtained naturally from a variety of food sources. Incorporating these foods into a balanced diet can help support overall nutrition.
Here are some common dietary sources of PABA:
- Organ meats (e.g., liver, kidneys)
- Brewer's yeast
- Whole grains
- Mushrooms
- Spinach
- Eggs
- Molasses
- Wheat germ
PABA Supplementation: Risks vs. Benefits
While PABA is available as a dietary supplement, potential benefits should be weighed against possible risks and side effects. Consulting a healthcare provider before starting any new supplement is essential, especially given the lack of recent research on its effectiveness for many of its purported uses.
| Aspect | Potential Benefits | Potential Risks & Downsides |
|---|---|---|
| Research Evidence | Limited and often older studies suggest benefits for some skin conditions and hair darkening. | Lacks modern, robust scientific evidence to support most claims, particularly for dermatological and hair-related issues. |
| Safety & Side Effects | Generally considered likely safe at low doses, especially when applied topically. | High oral doses (over 12g daily) can lead to serious side effects, including potential liver and kidney damage. Allergic reactions are possible. |
| Drug Interactions | None noted for low, dietary-level intake. | PABA may interfere with the effectiveness of sulfonamide antibiotics (sulfa drugs) and should not be taken together. |
| Recommended Intake | No recommended or standardized dosage exists, as it's not an essential vitamin. | Excessive supplementation, particularly at high doses, can be harmful. |
Conclusion
Para-aminobenzoic acid (PABA), also known as vitamin B10, is a unique compound with a history tied to the B-vitamin complex, but it is not a true, essential vitamin for humans. Its primary confirmed function is serving as a precursor for folate synthesis by gut bacteria, although this contribution is not enough to meet human needs. Historically, PABA was used in sunscreens for its UV-absorbing properties, a use later abandoned due to allergic reactions. While older, limited studies investigated its use for conditions like scleroderma and premature graying, these claims lack modern scientific support, and high-dose oral supplementation carries risks. For a healthy diet, focusing on whole foods like leafy greens, organ meats, and whole grains ensures adequate nutrition, including folate, without needing to rely on potentially risky PABA supplements.
For more comprehensive information on vitamins and supplements, you can visit authoritative sources such as Healthline.
