What mechanism is responsible for absorbing the vitamins in the gastrointestinal system of the child?
A 2-year-old girl who has recently been adoptedÂ from an impoverished family is brought to theÂ clinic by her adopted parents. They are concernedÂ because the child seems to be havingÂ trouble with her vision at in low-light conditions.Â
Water-soluble vitamins are transported by carrier-mediated mechanisms, and no coverage of intestinal absorption of certain vitamins is done through carrier-mediated processes. A variety of conditions regulates these processes, and the regulation of them involves transcriptional or post-transcriptional mechanisms.
The healthy microflora synthesizes many water-soluble vitamins. The small intestine is where vitamin osmosis happens. The best-studied mechanisms of absorption are for calcium and iron. Vitamins are better absorbed in the presence of food.
Micelle-mediated transport-the correct answer is c. this patient has vitamin a deficiency, which is characterized by early symptoms of night blindness, dry conjunctivae, and gray plaques, or late symptoms of corneal ulceration and necrosis leading to perforation and blindness. this deficiency is typically seen in children and pregnant women whose diets are deficient in vitamin a, especially those from southeast asia. vitamin a deficiency can also result from malabsorption following intestinal surgery, especially of the ileum. vitamins a, d, e, and k (the fat-soluble vitamins) are absorbed in the small intestine and absorption requires micelles formed with bile saltsanswer a is incorrect. fe2+ is absorbed in the small intestine and absorption requires apoferritin bindinganswer b is incorrect. vitamin b12 is absorbed in the terminal ileum and absorption requires intrinsic factoranswer d is incorrect. water-soluble vitamins are absorbed in the small intestine and absorption requires sodium contransportanswer e is incorrect. calcium is absorbed in the small intestine and absorption requires a vitamin d-dependent calcium binding protein.