Betakarotna

Betakarotna, commonly known as beta-carotene, is a natural pigment in plants and a member of the carotenoid family. It is a hydrocarbon with a long conjugated double-bond system and two beta-ionone rings at either end. Beta-carotene is a provitamin A carotenoid: the body can convert a portion of it into retinol (vitamin A), mainly in the intestinal mucosa and liver. Humans cannot synthesize beta-carotene and obtain it through diet or supplements.

Dietary sources and metabolism: Beta-carotene is abundant in colorful fruits and vegetables such as carrots, sweet potatoes, pumpkins, spinach, kale, cantaloupe, and mango. Dietary fat enhances its absorption, and cooking can improve bioavailability for some foods. The enzyme beta-carotene 15,15'-monooxygenase cleaves beta-carotene to retinol; conversion efficiency varies among individuals and is not 100 percent.

Biological role and deficiency: Vitamin A, derived from beta-carotene, supports vision, immune function, and maintenance of epithelial tissues. Severe vitamin A deficiency can cause night blindness and increased susceptibility to infections, particularly in areas with limited dietary variety. In many developed countries, deficiency is uncommon, and beta-carotene obtained from foods is typically safe and beneficial as part of a balanced diet.

Health evidence: Diets rich in fruits and vegetables containing beta-carotene are associated with various health benefits, though such effects are not solely attributable to beta-carotene. High-dose beta-carotene supplements have not shown cancer-preventive benefits and, in some groups—most notably current or former smokers and individuals exposed to asbestos—have been linked to an increased risk of lung cancer. Consequently, supplementing with high doses of beta-carotene is not recommended for cancer prevention in these populations. Beta-carotene from foods is considered safe, with notable potential for harmless skin discoloration (carotenodermia) at extremely high intakes.