While vitamin A was the first vitamin to be discovered, information about this essential nutrient is still being uncovered today. Researchers have long known that vitamin A helps with numerous bodily functions related to growth, reproduction, organ function, immunity, nerve health, and more. More recently, researchers have found that vitamin A also interacts with hormones. Vitamin A helps with the maintenance of the adrenal gland and also plays a role in the synthesis of other hormones, such as thyroid hormone.

Much of your vitamin A intake is through food. Vitamin A, in various forms, can be found in animal proteins such as meat, poultry, fish, and dairy as well as in green leafy vegetables and other brightly colored vegetables and fruits. In fact, vitamin A is so readily available that it is rare for people in developed societies to have a vitamin A deficiency. However, there is growing concern that many people may have too much vitamin A, which can cause hormone disruptions and other major health concerns.