Hi, I'm Maria Saracen from ArtufllyNourished.com. In this video for About.com I'm going to be talking about Vitamin A-what it is, where you can find it and why it's essential for good health.As you may already know, vitamin A is a fat soluble vitamin, which means that your body is able to store excess amounts in your liver. This is both a good thing and bad. Good, because your body can accumulate a reserve of Vitamin A should it need it. Bad, because if your reserves become too great, vitamin A can be toxic. Fortunately, the only time you have to worry about this happening is if you're consuming excessive amounts of preformed Vitamin A like retinyl acetate or retinyl palmitate, usually in the form of supplements. Animal products like liver, butter and eggs are the other sources of preformed Vitamin A but you have to eat massive quantities of these foods before you suffer any adverse effects from Vitamin A. Interestingly, Arctic Explorers who ate polar bear liver have been known to suffer from acute Vitamin A toxicity, but I don't think that's a risk for most of us.Carotenoids like beta-carotene, are called provitamin A which means that they must be converted into the active form of Vitamin A by your body. Provitamin A is found in plants and is not associated with any major adverse health effects. However, long-term and excessive consumption of carotenoids can turn your skin a yellow-orange color which is not harmful but it may not be the look you're going for.Two of the best food sources of vitamin A are sweet potatoes and beef liver. Spinach and carrots also pack a powerful punch. If a fruit or vegetable is orange in color, it's usually a good tip that it contains vitamin A, for example pumpkins, cantaloupe, mangoes, apricots and eggs. But even non-orange food can contain vitamin A, for example, black-eyed peas, sweet red peppers and broccoli. And of course, many other foods such as milk and ready-to-eat cereals are fortified with vitamin A.Vitamin A is vital for immune function and the proper development of the body's cells. The cardiac, nervous, respiratory and many other systems depend on Vitamin A to develop and function as they should. And as you may have heard, vitamin A is important for good vision, which is why my mother always told me to eat my carrots.Thanks so much for watching. To learn more about Vitamin A and other vitamins, please visit About.com.