About half of people see their blood pressure rise with salt; the other half are neutral. This decides whether low-sodium is medically mandatory or an unnecessary restriction that just makes food taste worse.

Choline demand varies 2–3× between people. Higher-need individuals see noticeable improvements in focus, fat metabolism, and liver function from eggs or supplementation—while others coast fine without thinking about it.

Copper is a behind-the-scenes player—affecting iron absorption, collagen production, and antioxidant defense. The catch: both deficiency and excess cause problems, and they look surprisingly similar. Your regulation pattern tells you which direction to watch.

Folate requirements vary widely—especially during pregnancy, high stress, or rapid cell turnover. Knowing yours prevents the subtle deficiency that quietly affects mood, energy, and long-term health without obvious symptoms.