Which vitamin is necessary for the absorption and use of calcium?

Vitamin D is essential for the absorption and utilization of calcium in the body. It plays a crucial role in maintaining bone health by facilitating the gastrointestinal absorption of calcium from the diet. Without adequate vitamin D, even if calcium intake is sufficient, the body cannot effectively absorb it, which can lead to weakened bones or conditions such as osteoporosis and rickets. The active form of vitamin D, calcitriol, directly increases the intestinal absorption of calcium and phosphate, thereby supporting mineralization of bone. This relationship underscores the importance of vitamin D in calcium metabolism and overall skeletal health.