Vitamin D helps regulate the amount of calcium and phosphate in the body. These nutrients are needed to keep bones, teeth and muscles healthy. A lack of vitamin D can lead to bone deformities such as rickets in children, and bone pain caused by a condition called osteomalacia in adults
It depends on the type of drug you mean, such as medicinal drugs like marijuana, or bad drugs like cocaine or heroine. But the best answer(in my opinion) is B.