Which nutritional factor positively influences bone density?

Vitamin D intake plays a crucial role in bone density as it is essential for calcium absorption in the intestines. Calcium is a primary component of bone tissue, and without sufficient vitamin D, the body cannot effectively utilize dietary calcium to strengthen bones. This connection highlights the importance of vitamin D in maintaining optimal bone health, especially considering its impact on preventing conditions such as osteoporosis.

While protein is important for overall health and can contribute to bone repair and maintenance, its direct influence on bone density is less pronounced than that of vitamin D. Carbohydrates serve mainly as an energy source and do not directly relate to bone density. Calcium intake is also vital, but vitamin D serves as the key facilitator in ensuring that calcium is absorbed and utilized effectively. Therefore, the correct choice reflects the specific role of vitamin D in enhancing bone mineralization and density.