Nutritionist for Salt Lake City, Utah

Salt Lake City has a health problem it mostly stopped noticing. Every winter the inversion traps a lid of cold air over the valley and the air quality drops to among the worst in the country for weeks at a time. Inflammation doesn't care whether you've normalized it. People arrive in February wondering why their energy fell off a cliff, and the honest answer often starts with what they've been breathing since November.

The other pattern here is desk-shaped. The tech corridor running south out of the city has filled downtown with people who sit for ten hours, eat at their screen, train hard at 6am to compensate, and can't understand why the compensating stopped working somewhere around forty. That combination — sedentary days, hard training, and a chronic inflammatory load — shows up on a metabolic panel with real clarity.

Add altitude to both. At around 4,300 feet, hydration, recovery and sleep all behave differently than they did wherever you moved from, and vitamin D runs low across the whole state for a good part of the year.