Vitamin C plays a role in regulating the storage of which nutrient?

Vitamin C is essential for various physiological functions, and one of its important roles is in the regulation of iron storage and metabolism. It enhances the absorption of non-heme iron from plant sources in the diet, which is particularly significant given that iron deficiency is a common concern. Vitamin C can reduce ferric iron (Fe3+) to ferrous iron (Fe2+), a form that is more easily absorbed in the intestines.

Moreover, Vitamin C also assists in the mobilization of iron from storage sites such as the liver and spleen, thereby playing a crucial role in maintaining adequate iron levels within the body. This is particularly important for preventing anemia and ensuring efficient oxygen transport in the bloodstream.

The other nutrients listed—calcium, potassium, and magnesium—do not have a direct regulatory relationship with Vitamin C in terms of storage and absorption as iron does. Vitamin C's primary association in this context revolves around iron metabolism, making it the correct choice.