In which organ is Vitamin A primarily stored?

Vitamin A is primarily stored in the liver.

Vitamin A is a fat-soluble nutrient, meaning the body can retain it rather than excreting excess amounts immediately in urine. After absorption, much of it is transported to the liver, where it is converted into storage forms called retinyl esters. In healthy people, roughly 80–90% of the body’s vitamin A reserves may be held in the liver, although the exact proportion varies.

The liver releases vitamin A when tissues need it. The nutrient supports vision, immune function, reproduction, and maintenance of skin and other epithelial tissues. Much of the stored vitamin A is held in specialized hepatic stellate cells, rather than floating freely in the bloodstream.

A common mix-up is confusing vitamin A with beta-carotene. Beta-carotene is a plant pigment and provitamin A carotenoid that the body can convert into vitamin A; it is not identical to preformed vitamin A from foods such as liver, eggs, and dairy. Because vitamin A accumulates, excessive supplements can cause toxicity, so more is not always better.