Which vitamin is known for its role in calcium absorption and bone health?

Vitamin D is essential for calcium absorption in the intestines and plays a critical role in maintaining bone health. Its primary function is to enhance the body's ability to absorb calcium, which is crucial for the development and maintenance of strong bones. When vitamin D levels are adequate, the body can more effectively utilize dietary calcium, preventing issues such as rickets in children and osteoporosis in adults.

Vitamin D acts as a hormone in the body and regulates various aspects of calcium metabolism, including the promotion of calcium reabsorption in the kidneys and modulation of calcium levels in the bloodstream. In contrast, the other vitamins listed do not have the same direct impact on calcium absorption or bone health. For instance, vitamin A is primarily involved in vision and immune function, vitamin B12 is crucial for red blood cell production and neurological function, and vitamin C plays a role in collagen synthesis and antioxidant protection, but it does not directly influence calcium absorption. Thus, vitamin D stands out as the key nutrient for calcium absorption and maintaining bone health.