Micelle formation is necessary for the intestinal absorption of which vitamin?

Micelle formation is essential for the intestinal absorption of fat-soluble vitamins, which include vitamins A, D, E, and K. In particular, vitamin B12 is a water-soluble vitamin that does not require micelle formation for absorption. Instead, vitamin B12 absorption primarily takes place in the ileum and involves intrinsic factor, a glycoprotein produced by the stomach.

The process of micelle formation involves the emulsification of dietary fats in the presence of bile salts, allowing fat-soluble vitamins to be incorporated into micelles for absorption into the intestinal epithelium. Vitamin A and D, being fat-soluble, rely on this process, while vitamin C, also water-soluble, is absorbed directly without the need for micelle formation.

In this context, while it is understood that micelle formation is critical for certain vitamins, it does not apply to vitamin B12, making the association with micelles incorrect. Therefore, recognizing the types of vitamins and their absorption mechanisms is vital for understanding nutrient absorption in humans.