The human body is an incredibly complex machine, and science is still far from uncovering ALL the secrets of how ALL its components work together. What we know for sure, however, is that such a complex system requires quality fuel—and that comes in the form of energy (calories), as well as the essential vitamins and minerals to support its tasks.
Some vital processes that heavily rely on adequate micronutrient intake include sperm production, hair growth, deep sleep, thyroid function, and testosterone synthesis, of course. Lacking essential micronutrients means having an increased risk of impairing these crucial processes.
*You can also find the links to the clinical studies that back up these claims in each individual article on the topic.