Vitamin A (retinal) is an essential vitamin, meaning that you must have it to stay alive. It is required for the health of the eyes, lungs, skin, bones, intestines, and immune system, and for red blood cell production. Beta-carotene, which converts at low rates to vitamin A in the body, is not an essential nutrient and is not required for life. While it is commonly assumed that beta-carotene always converts to vitamin A as needed, published studies indicate that almost half (45%) of normally healthy people cannot absorb or convert beta-carotene into vitamin A adequately.
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