# item.guide
Side-by-Side Comparison Essential Vitamins & Minerals

Iron (Heme & Non-Heme) vs. Potassium (Elemental K)

Comparing 2 standards across 10 specifications. 10 key differences identified.

Comparing:
Iron (Heme & Non-Heme)
Potassium (Elemental K)

Iron is an essential redox trace element central to hemoglobin oxygen transport, myoglobin storage, and mitochondrial electron transport chain cytochromes. Adult RDA is 8mg (men/post-menopausal women) / 18mg (pre-menopausal women), with a Tolerable Upper Limit of 45mg/day.

View full Iron (Heme & Non-Heme) spec sheet →

Potassium is the primary intracellular cation (140 mEq/L intracellular vs 4 mEq/L extracellular), maintaining the cellular resting membrane potential via the Na+/K+-ATPase pump and regulating vascular tone. Adequate Intake (AI) is 3,400 mg (men) / 2,600 mg (women).

View full Potassium (Elemental K) spec sheet →

Specification Comparison Table

10 Parameters
Parameter / Spec
Nutrient Type
Essential Trace Mineral Essential Macromineral / Major Intracellular Electrolyte
Tolerable Upper Limit (UL)
45 mg / day (Hemochromatosis / Fenton reaction oxidative stress) None Established (Whole foods; healthy kidneys clear excess; renal impairment requires clinical restriction)
Chemical Forms
Heme Iron (Fe2+ Porphyrin - Animal), Non-Heme Iron (Fe3+ Ferric / Fe2+ Ferrous - Plants/Supplements) Potassium Citrate, Potassium Chloride (KCl / Salt substitute), Potassium Gluconate
Primary Biological Function
Hemoglobin O2 transport, Myoglobin O2 storage, Cytochrome c electron transport, Catalase Na+/K+-ATPase resting membrane potential (-70mV), Cardiac myocardial repolarization, Endothelial nitric oxide vasodilation (lowers blood pressure), Blunts sodium-induced fluid retention
Deficiency Condition
Microcytic Hypochromic Anemia, Severe fatigue, Restless legs syndrome, Pica Hypokalemia (Serum K+ < 3.5 mmol/L): Cardiac arrhythmias (U-waves, ventricular tachycardia), Muscle weakness, Ileus, Hypertension
Top Whole Food Sources
Beef Liver, Oysters, Duck Breast, Beef Ribeye, Lentils, Spinach, Dark Chocolate Baked Russet Potato (with skin), Orange Sweet Potato, Spinach, Bananas, Atlantic Salmon, Black Beans, Hass Avocado, Coconut Water
Adult RDA / RDI
8 mg (Men) / 18 mg (Women 19–50) / 27 mg (Pregnancy)
Bioavailability Difference
Heme: 15–35% absorption (uninhibited); Non-Heme: 2–20% (inhibited by phytates/calcium, boosted by Vitamin C)
Adult Adequate Intake (AI)
3,400 mg / day (Men) / 2,600 mg / day (Women) (WHO Target: >3,510 mg/day)
Dietary Sodium-to-Potassium Ratio
Ancestral human ratio was 1:4 (Na:K); modern Western diets average 2:1, significantly contributing to hypertension