It’s funny, the things that are considered lipids. But of course, when an entire class of compounds is defined by it solubility in water (rather than it’s biological function, for instance), you get funny things. Like fats and vitamin A being lumped together. Like vitamin E, vitamin A is a fat soluble vitamin.
There are several forms of vitamin A: preformed vitamin A (including retinol) from animal sources and pro-vitamin A (carotenoids like beta-carotene) from plant sources [1, 2]. In the human body, vitamin A becomes retinal and retinoic acid.
You might notice the “retina” in the names and be thinking about how your mom told you “Carrots are good for your eyes.” It’s true: vitamin A is essential to sight, especially night vision. Retinal attaches to a protein in your eye called rhodopsin and when light hits the retinal molecule, it changes shape. This leads to the rhodopsin protein changing shape, too, and that signals that there is light to see by [1, 2].
Pro-vitamin A carotenoids are derived from plant pigments–the same ones that make those pretty fall colored-leaves–and this is what leads to that vegetable-induced glow. Besides that, topically applied vitamin A is associated with cell turnover, leading less inflammation and fewer blemishes . Vitamin A is also important for a well-functioning immune system. This includes maintaining skin’s barrier function (you know your skin is your first line of defense against disease,right? Taking care of it is a top priority) .
Vitamin A, being fat-soluble, can cause problems both when you don’t get enough and when you get too much. However, this seems only to be a problem with preformed vitamin A–not beta-carotene . So, no reason to skip out on the fruits and veggies!