Magnesium is an essential mineral that plays a crucial role in many bodily functions, including energy production. It is involved in the metabolism of ATP, the main energy currency of cells, and also helps to regulate muscle and nerve function. However, magnesium deficiency can lead to tiredness and fatigue as it impairs the body's ability to produce and utilize energy efficiently. Low magnesium levels can also disrupt sleep patterns and cause muscle weakness, which can contribute to feelings of tiredness and weakness.