Final answer:
Magnesium serves several functions in the body, including acting as a co-factor for enzymes, contributing to bone structure, and aiding in vitamin D metabolism; hence, all the given options are correct.D. All of them
Step-by-step explanation:
Magnesium is a versatile mineral with numerous roles in the human body. One significant function of magnesium is that it acts as a co-factor for over 300 enzyme systems that regulate diverse biochemical reactions. Secondly, magnesium plays a crucial part in the bone structure; about 70% of the body's total magnesium content combines with calcium and phosphorus to form the complex salts in bones. Lastly, magnesium supports the metabolism of vitamin D, which is essential for the absorption of calcium and overall bone health.
To summarize the answer to the provided question: All of the options (A, B, and C) are correct. Magnesium is a co-factor for enzyme systems, a mineral in bone structure, and a supporter of vitamin D metabolism.