Iron (for At-Risk Populations)

Iron is the most critical supplement for at-risk populations, as deficiency affects 1.6 billion people globally—outperforming #7 Zinc Picolinate in addressing the world's most common nutritional shortfall. Supplementation with 18–27 mg elemental iron as ferrous bisglycinate minimizes gastrointestinal side effects while restoring ferritin stores. However, men and postmenopausal women should only supplement if testing confirms deficiency, since excess iron causes oxidative damage and iron overload affects 1 in 200 people of European descent.