Final answer:
Exceeding the recommended intake of Vitamin A by consuming more than 3000 ug/day can lead to hypervitaminosis A with symptoms such as nausea and potentially more severe consequences like keratomalacia and liver damage.
Step-by-step explanation:
Consuming more than 3000 micrograms (ug) per day of Vitamin A can lead to several negative health consequences. At such high levels, Vitamin A can cause hypervitaminosis A, which is characterized by symptoms such as nausea, vomiting, and headache. Over time, excessive Vitamin A intake can result in more severe effects such as keratomalacia, a condition that leads to dryness of the eye, skin, and can affect the keratinization process in various bodily systems including the respiratory, intestinal, and urinary tracts. Moreover, it may also result in necrosis of hepatic cells, indicating liver damage. Vitamin A is essential for healthy skin, bones, teeth, and vision; however, it should be consumed within the recommended daily limit to avoid toxicity.
Vitamin A is transported in the body bound to retinol-binding protein (RBP) and is stored in the liver until needed by the body. Its primary dietary sources are through the intake of beta-carotenes (from plant sources) and retinyl esters (from animal sources). An adequate intake of Vitamin A is crucial as it is essential for visual health and the immune system, among other biological functions.