What vitamin is important for calcium absorption?

Vitamin D plays a crucial role in calcium absorption within the body. It enhances the intestinal absorption of calcium, promoting the mineral's availability for bone health and other physiological functions. When vitamin D levels are adequate, the intestines can more effectively absorb calcium from food. This is particularly important for maintaining healthy bones, as insufficient calcium absorption can lead to conditions such as osteoporosis.

In contrast, other vitamins listed do not have this specific role in calcium absorption. Vitamin A supports vision and immune function, vitamin C is vital for collagen synthesis and immune response, and vitamin K primarily aids in blood clotting and possibly bone metabolism but is not directly involved in the absorption of calcium in the intestines. Thus, vitamin D's unique ability to facilitate calcium absorption makes it the correct choice in this context.