The deficiency of vitamin D leads to

The correct answer is "rickets." Vitamin D is essential for the body to absorb calcium, which is needed for the development and maintenance of strong bones. Without enough vitamin D, bones become soft and weak, a condition known as rickets in children and osteomalacia in adults. Rickets can lead to bone pain, muscle weakness, and an increased risk of fractures. In severe cases, it can cause deformities of the skeleton, such as bowed legs or an abnormal curvature of the spine. Vitamin D deficiency can also increase the risk of developing osteoporosis, a condition in which bones become fragile and are more likely to break. Vitamin D is often called the "sunshine vitamin" because the body can produce it when the skin is exposed to sunlight. However, it can also be obtained from certain foods, such as fatty fish, egg yolks, and fortified milk and cereals. In some cases, vitamin D supplements may be needed to ensure adequate intake.