BIO 111 Lecture Notes - Lecture 15: Beta-Carotene, Visual Phototransduction, Zeaxanthin
24 Dec 2020
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Document Summary
Definition: essential, non-caloric, organic substances needed in only small amount for the proper functioning of our body. Body is unable to synthesize enough of the compound to maintain health. Absence of the compound from the diet for a defined period produces deficiency symptoms that can be reversed when the compound is resupplied. Fat soluble vitamins- a, d, e, and k. Absorbed in chylomicrons, stored in liver and fatty tissue, can build up to toxic levels. Water soluble vitamins- c and b vitamins. Absorbed in capillaries, in general not stored to a great degree, excess excreted in urine. Storage of vitamins within the body and over-supplementation can over time cause the level of some vitamins to build up. Vitamin a has the most potential for reaching toxic levels. Vitamins can be lost between the time a fruit or vegetable is picked and the time it is eaten. Improper storage and excessive cooking can destroy vitamins- especially water- soluble vitamins.
