Beta Carotene Information, Benefits and Side Effects
Beta carotene is one of the (nearly) 600 different carotenoids—plant pigments that give red/orange fruits and vegetables their color. It’s best known as a precursor to vitamin A (retinol) in the body.
While vitamin A, a fat-soluble nutrient, can be toxic if taken in excess, beta-carotene can be safely ingested even in large quantities. This is why many multivitamin supplement formulas rely on beta-carotene to supply part—and sometimes all—of their vitamin A activity.
Food sources of beta-carotene include dark leafy greens, carrots, sweet potatoes, squash, apricots and broccoli. The vitamin A activity of beta-carotene from foods is approximately 1/12 that of retinol, thus, it would take 12 mcg of beta carotene to provide the equivalent of 1 mcg of vitamin A…assuming it’s even needed. Conversion decreases when vitamin A stores are sufficient.
Adult women need about 700 micrograms/day of vitamin A, and adult men need about 900 micrograms/day. This is the equivalent of about 8.4–10.8 mg of beta-carotene—an amount that can easily be met by consuming 1–2 daily servings of beta-carotene-rich foods.
In addition to its vitamin A activity, beta-carotene is a powerful antioxidant.
High intakes of foods rich in carotenoids have been associated with reduced risks of cancer and heart disease… thus, many studies have been conducted to examine the possible therapeutic uses of beta-carotene for preventing/treating these diseases.
The results of these studies, unfortunately, have been equivocal, at best. While beta-carotene itself is effective against harmful free radicals, “carotenoid breakdown products” are not.
In fact, they function, paradoxically, as pro-oxidants, and can be highly damaging. This may explain why monotherapy with isolated beta-carotene has failed to reduce cancer or cardiovascular disease incidence/mortality.
High dose beta-carotene supplementation may even increase the risk of lung cancer—especially in smokers.
Are there any benefits to beta-carotene supplementation? It’s difficult to find studies—particularly human studies—that provide unambiguous, reliable evidence of any benefits beyond its pro-vitamin A function for healthy people. Most medical/nutrition professionals agree: it’s best to get carotenoids from foods, rather than supplements.
What about therapeutic benefits?
There may be a few… for example, beta-carotene is the treatment of choice for erythropoietic protoporphyria—a rare genetic disorder that causes extreme photosensitivity.
Beta-carotene may also help alleviate oral lichen planus and exercise-induced asthma; delay the progression of age-related macular degeneration and improve the quality of life for patients with cystic fibrosis.
While beta-carotene supplements can usually be taken in significant amounts without direct toxicity, taking too much can cause diarrhea or stomach upset. Large amounts of beta-carotene can also give the skin a yellowish tinge (carotenemia). The tinge is harmless and will go away when excess beta-carotene is removed from the diet.
Beta carotene can be purchased for a reasonable price almost anywhere, and online we recommend BodyBuilding.com, one of our recommended online retailers.
