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

Potassium (Elemental K) vs. Vitamin B12 (Cobalamin)

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

Comparing:
Potassium (Elemental K)
Vitamin B12 (Cobalamin)

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 →

Vitamin B12 is a cobalt-containing water-soluble corrinoid synthesized exclusively by microorganisms. Adult RDA is 2.4µg/day (no Upper Limit established), required for DNA synthesis, methionine synthase homocysteine conversion, and myelin sheath maintenance.

View full Vitamin B12 (Cobalamin) spec sheet →

Specification Comparison Table

10 Parameters
Parameter / Spec
Nutrient Type
Essential Macromineral / Major Intracellular Electrolyte Water-Soluble Corrinoid Vitamin
Tolerable Upper Limit (UL)
None Established (Whole foods; healthy kidneys clear excess; renal impairment requires clinical restriction) None Established (Extremely low toxicity)
Chemical Forms
Potassium Citrate, Potassium Chloride (KCl / Salt substitute), Potassium Gluconate Methylcobalamin (Active), Adenosylcobalamin (Active), Cyanocobalamin (Stable synthetic)
Primary Biological Function
Na+/K+-ATPase resting membrane potential (-70mV), Cardiac myocardial repolarization, Endothelial nitric oxide vasodilation (lowers blood pressure), Blunts sodium-induced fluid retention Methionine synthase cofactor, Methylmalonyl-CoA mutase cofactor, Myelin integrity, Erythropoiesis
Deficiency Condition
Hypokalemia (Serum K+ < 3.5 mmol/L): Cardiac arrhythmias (U-waves, ventricular tachycardia), Muscle weakness, Ileus, Hypertension Pernicious / Megaloblastic Anemia, Irreversible Neurological Peripheral Neuropathy
Top Whole Food Sources
Baked Russet Potato (with skin), Orange Sweet Potato, Spinach, Bananas, Atlantic Salmon, Black Beans, Hass Avocado, Coconut Water Oysters, Beef Liver, Sardines, Salmon, Beef, Dairy, Eggs (Absent in unfortified plant foods)
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
Adult RDA / RDI
2.4 µg / day (2.6µg pregnancy, 2.8µg lactation)
Absorption Mechanism
Requires Gastric Acid, R-Protein, and Intrinsic Factor (IF) via Ileal Cubam receptors