beetakaroteenin

Beetakaroteenin, more commonly known as beta-carotene, is a carotenoid pigment and a provitamin A compound found in many fruits and vegetables. It gives orange, yellow, and red colors to foods such as carrots, sweet potatoes, pumpkins, spinach, kale, apricots, and mangoes.

Chemically, beta-carotene is a long conjugated polyene with two beta-ionone rings at each end. It exists in trans and several cis isomers; natural dietary forms are mainly all-trans, though processing and storage can produce cis isomers. Beta-carotene is absorbed with dietary fat and transported by chylomicrons. In the intestinal cells, the enzyme BCMO1 cleaves beta-carotene to retinal, which can be reduced to retinol (vitamin A) or oxidized to retinoic acid for signaling.

Role in nutrition and health: It serves as a precursor to vitamin A, contributing to vitamin A status when dietary vitamin A is limited. It also has antioxidant properties in laboratory studies, but in humans its in vivo effects are more complex. Adequate intake from food helps prevent vitamin A deficiency, which can cause night blindness and increased susceptibility to infections. High-dose beta-carotene supplements have not shown consistent disease-preventive benefits and, in some populations (notably smokers), have been associated with an increased risk of lung cancer and other adverse effects.

Uses and safety: Beta-carotene is used as a natural food pigment (color additive E160a) and is available in dietary supplements. Excessive intake from supplements can cause carotenodermia, a harmless orange discoloration of the skin. For best absorption, it should be consumed with dietary fats.