Vitamin A (as beta-carotene from Blakeslea trispora fungus)

Vitamin A, also called retinol, is a fat-soluble vitamin that is essential for humans. Adequate intake is important for normal vision and immune function. Dietary vitamin A can be provided as both preformed vitamin A and provitamin A carotenoids that are precursors to vitamin A. Preformed vitamin A is abundant in animal-derived foods like liver, kidney, eggs, and dairy products. Carotenoids, like beta-carotene, are found in darkly colored fruits and vegetables. Preformed vitamin A is efficiently absorbed through the intestines, while carotenoids may either be absorbed through the intestines intact or cleaved to form vitamin A prior to absorption. The proportion of beta-carotene converted to vitamin A decreases as beta-carotene intake increases, limiting the risk of vitamin A toxicity 1.

Beta-carotene, also called provitamin A, is a member of a group of plant-produced compounds called carotenoids, which serve as precursors to vitamin A. Beta-carotene is a potent antioxidant. The ultimate source of all vitamin A is from the carotenes, and beta-carotene has the highest vitamin A activity 2. Beta-carotene is particularly abundant in orange vegetables and fruit, and may be directly added to foods as a vitamin supplement 3.

Carotenoids may either be absorbed through the intestines intact, or be cleaved to form vitamin A prior to absorption. There is no Recommended Dietary Allowance (RDA) for beta-carotene or other provitamin A carotenoids. However, dietary provitamin A carotenoids have vitamin A activity that can be expressed as retinol activity equivalents (RAEs). The RDA for RAEs is 900 µg/day for men and 700 µg/day for women 1. Beta-carotene supplementation in humans is likely safe over long periods of time.

Blakeslea trispora is a fungus that can be used as a source of carotenoids, such as beta-carotene, gamma-carotene and lycopene, for dietary supplements 4,5.

This ingredient can be found in the following products in United States:


  1. Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, D.C.: National Academy Press, 2002.
  2. Ensminger AH, Ensminger ME, Konlande JE, Robson JRK. The Concise Encyclopedia of Foods and Nutrition. Boca Raton, Florida: CRC Press, 1995.
  3. Food and Drugs. Title 21, U.S. Code of Federal Regulations. 1999. 21CFR. Ref Type: Bill/Resolution
  4. Olempska-Beer Z. U.S. Food and Drug Administration. Lycopene from Blakeslea trispora Chemical and Technical Assessment. 2006. College Park, Maryland.
  5. Jeong J, Lee I, Kim S, Park Y. Stimulation of beta-carotene synthesis by hydrogen peroxide in Blakeslea trispora. Biotechnology Letters 1999;21:683–6.