Final answer:
Vitamin D3 is important for proper bone development, as it plays a crucial role in the development of bones, teeth, and skin. It also helps maintain eyesight, enhances the immune system, aids in fetal development, and regulates gene expression.
Step-by-step explanation:
Vitamin D3 is important for proper bone development. It is critical to the development of bones, teeth, and skin. Vitamin D helps maintain eyesight, enhances the immune system, aids in fetal development, and regulates gene expression.