What is the active form of vitamin A?

What is the active form of vitamin A?

• A. Retinol
• B. Carotenoids
• C. Riboflavin
• D. Tocopherol

Answer: (A)

Vitamin A functions through several related compounds, but the form that serves as the main active, usable form in the body is retinol. Retinol is the alcohol form that circulates in the blood and is stored in the liver, ready to be converted as needed. From retinol, the body can make retinal, which is essential for vision, and retinoic acid, which acts like a hormone to regulate gene expression and cell growth. Carotenoids such as beta-carotene are precursors that the body can convert into retinol, but they aren’t active vitamin A themselves. Riboflavin and tocopherol are vitamins other than A (B2 and E), not forms of vitamin A.

Vitamin A functions through several related compounds, but the form that serves as the main active, usable form in the body is retinol. Retinol is the alcohol form that circulates in the blood and is stored in the liver, ready to be converted as needed. From retinol, the body can make retinal, which is essential for vision, and retinoic acid, which acts like a hormone to regulate gene expression and cell growth. Carotenoids such as beta-carotene are precursors that the body can convert into retinol, but they aren’t active vitamin A themselves. Riboflavin and tocopherol are vitamins other than A (B2 and E), not forms of vitamin A.