Stress has become so normalized in modern life that most of us have stopped questioning it. We accept the tight shoulders, the shallow breathing, the racing thoughts that follow us into bed. We reach for coffee in the morning and melatonin at night, and somewhere in between we try to hold it all together.

The transition into fall is often described in terms of aesthetics. Cooler air. Shorter days. A shift in light that makes everything look slightly different in the late afternoon. What rarely enters that conversation is what the body is doing at the same time, beneath the surface, in response to those same environmental changes.

There is a mineral involved in more than 300 biochemical reactions in the human body. It participates in the production of cellular energy, the regulation of blood pressure, the synthesis of protein, the control of blood sugar, the transmission of nerve signals, and the contraction and relaxation of muscle tissue. It is the fourth most abundant mineral in the body, present in every cell you have. It is also the mineral that most adults in the developed world are chronically short on, often without knowing it.