Question

How are vitamins A, D, E, and K absorbed by the body?

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How are vitamins A, D, E, and K absorbed by the body?

by binding to intrinsic factor to trigger receptor-mediated endocytosis

by active transport of vitamin pumps in the intestinal epithelia

by being incorporated into micelles

by direct simple diffusion in the jejunum

Answer 1

Vitamins A, D, E and K absorption

The A, D, E and K are called fat soluble vitamins. As the name indicates they are not soluble in water All these nutrients are absorbed by simple diffusion. Due to their insolubility in water they cannot reach the blood stream directly. They first incorporated into small, spherical, water soluble droplets called micelles with the help of the bile salts and phospholipids in the intestinal lumen. A micelle is an aggregate of many molecules. From the micelles fatty acids, glycerides, sterols and fat soluble vitamins are absorbed into the intestinal cells. This is how the fat soluble vitamins are absorbed in jejunum through diffusion by incorporating into micelles.

So the answer is by being incorporated into micelles.

Note: The water soluble vitamins like vit B and C., Monosaccharides and amino acids, salts are absorbed by active transport and water is absorbed by osmosis.