Vitamin A (Retinol) Unit Converter

Vitamin A is a fat-soluble vitamin that your body needs for healthy vision, immune function, cell growth, and reproduction. The test measures retinol, the main circulating form of vitamin A in your blood.

Your body obtains vitamin A from two dietary sources: preformed vitamin A (retinol) from animal products like liver, eggs, and dairy, and provitamin A carotenoids (such as beta-carotene) from colorful fruits and vegetables, which your body converts into retinol.

The liver stores 80-90% of your body's vitamin A, and serum levels are tightly regulated. Blood levels only drop once liver stores are severely depleted, which means a low test result indicates significant deficiency.

Vitamin A is obtained entirely from your diet. Preformed vitamin A (retinol) comes from animal sources like liver, fish, eggs, and dairy. Provitamin A carotenoids from colorful plant foods are converted to retinol in your intestine. The liver stores most of your body's vitamin A and releases it into the bloodstream bound to retinol-binding protein.