Beta-Carotene vs. Preformed Vitamin A: What’s the Difference?
Understanding the form of Vitamin A Dr. Wayne Diamond chose for Herpanacine Skin & Immune Support
When reading a Supplement Facts panel, seeing the words “Vitamin A” doesn’t necessarily tell the whole story. Vitamin A can come from different sources, and understanding the source is important when evaluating a dietary supplement.
When Dr. Wayne Diamond formulated Herpanacine and our other formulas, he chose beta-carotene as the formula’s source of Vitamin A.
Beta-carotene is a provitamin A carotenoid, which is different from preformed Vitamin A, such as retinol and retinyl esters.
There Are Different Sources of Vitamin A
According to the National Institutes of Health (NIH) Office of Dietary Supplements, Vitamin A comes from two primary dietary sources:
- Preformed Vitamin A, which includes forms such as retinol and retinyl esters.
- Provitamin A carotenoids, which the body can convert into Vitamin A. Beta-carotene is the most common provitamin A carotenoid found in foods and dietary supplements.
Dr. Wayne Diamond chose beta-carotene as the source of Vitamin A in the Herpanacine formula.
Why Does the Form of Vitamin A Matter?
The distinction between beta-carotene and preformed Vitamin A becomes particularly important when discussing upper intake levels and Vitamin A toxicity.
The NIH explains that the Tolerable Upper Intake Levels (ULs) established for Vitamin A apply to preformed Vitamin A. For adults, the UL for preformed Vitamin A is 3,000 mcg RAE per day.
The NIH Food and Nutrition Board has not established a Tolerable Upper Intake Level for beta-carotene or other provitamin A carotenoids; However, the NIH does explain that high intakes of beta-carotene do not cause the same problems associated with high intakes of preformed Vitamin A.
This is why simply seeing “Vitamin A” on a Supplement Facts panel without considering the source of that Vitamin A can give an incomplete picture.
What About Beta-Carotene Safety?
Although beta-carotene does not cause the same problems associated with high intake of preformed vitamin A, that does not mean that more is always better or that beta-carotene supplementation is appropriate for everyone.
The NIH notes that two studies using high-dose beta-carotene supplements found an increased risk of lung cancer in people who smoke, formerly smoked, or have had asbestos exposure.
As with any dietary supplement, individual circumstances matter. Consumers with questions about whether a dietary supplement is appropriate for them should consult an appropriate healthcare professional.
Why Ingredient Details Matter
Dr. Wayne Diamond researched and developed the Herpanacine formula with 11 ingredients, including beta-carotene as its source of Vitamin A.
At Diamond Formulas, we believe consumers should know not only what nutrients are in their supplements, but also the forms and sources of those nutrients.
Understanding the difference between beta-carotene and preformed Vitamin A provides important context when reading a Supplement Facts panel or researching information about Herpanacine.
Sources
NIH Office of Dietary Supplements — Vitamin A and Carotenoids: Consumer Fact Sheet
NIH Office of Dietary Supplements — Vitamin A and Carotenoids: Health Professional Fact Sheet
Last reviewed: September 2026
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.