CSSD Practice Exam 2025 – Complete Study Resource

Vitamin D is essential for regulating calcium metabolism in the body. It facilitates the absorption of calcium from the gastrointestinal tract, ensuring that the body maintains adequate calcium levels, which are crucial for bone health and various bodily functions. Without sufficient vitamin D, the body's ability to absorb calcium is compromised, which can lead to bone density issues and increase the risk of fractures or conditions like osteoporosis.

Calcium metabolism also involves the regulation of parathyroid hormone and calcitonin, hormones that control calcium levels in the blood. Vitamin D, along with these hormones, works to balance calcium levels, making it a key nutrient in this process.

Other nutrients, while important in different contexts, do not directly play the same role in the regulation of calcium metabolism. Vitamin A primarily supports vision and immune function, and vitamin E acts as an antioxidant. Vitamin K is more associated with blood clotting and bone health but does not primarily regulate calcium absorption in the same direct way that vitamin D does.