Answer to Question 1
c
Answer to Question 2
Vitamin D helps the body to absorb calcium to maintain strong bones. If the diet supplies enough calcium for the body's needs, it will not have to be taken out of the bones to maintain the blood calcium levels. Calcium also helps the muscles to initiate contraction that will aid in their function and strength generation. Calcium is also needed for the release of acetylcholine from the motor neurons. Acetylcholine triggers the muscles to contract when signaled from the motor neuron. This function is essential for optimal muscle function and for coordination in the athlete.
Vitamin D mainly comes from fish and other meats. It is hard to get enough vitamin D from foods. Vitamin D can also be made from precursors in the skin when it is exposed to the sunlight. Active vitamin D is made by chemical reactions in the liver and kidneys. If sunlight or dietary sources are lacking, an athlete can use a vitamin D supplement.