Final answer:
The absorption of calcium in the body requires Vitamin D, which is critical for bone health. It enables the active transport of calcium across the intestinal mucosa and helps maintain normal serum calcium and phosphate levels.
Step-by-step explanation:
The nutrient needed for the absorption of calcium in the body is Vitamin D. Vitamin D facilitates the absorption of calcium by promoting the synthesis of specific calcium binding proteins which aid in the active transport of calcium across the small intestinal mucosa. Without sufficient vitamin D, the absorption of dietary calcium is significantly hampered, leading to potential bone health issues such as rickets in children and osteoporosis in adults.
Furthermore, vitamin D is essential for maintaining normal serum concentrations of calcium and phosphate, which are vital for bone health, muscle contraction, and various cellular processes. A deficiency in vitamin D can decrease calcium absorbed in the intestines, eventually depleting calcium stores in the skeletal system. Therefore, maintaining adequate levels of vitamin D is crucial for bone health and overall well-being.