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

Sodium (Elemental Na) vs. Vitamin B12 (Cobalamin)

Comparing 2 standards across 11 specifications. 11 key differences identified.

Comparing:
Sodium (Elemental Na)
Vitamin B12 (Cobalamin)

Sodium is the principal extracellular cation (135–145 mEq/L extracellular), maintaining extracellular fluid volume, plasma osmolality, and driving secondary active transport. Adequate Intake (AI) is 1,500 mg/day, with a Chronic Disease Risk Reduction (CDRR) limit of 2,300 mg/day.

View full Sodium (Elemental Na) 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

11 Parameters
Parameter / Spec
Nutrient Type
Essential Macromineral / Major Extracellular Electrolyte Water-Soluble Corrinoid Vitamin
Chemical Forms
Sodium Chloride (NaCl, 39.3% Na by weight), Monosodium Glutamate (MSG, 12.3% Na), Sodium Bicarbonate (27.4% Na) Methylcobalamin (Active), Adenosylcobalamin (Active), Cyanocobalamin (Stable synthetic)
Primary Biological Function
Extracellular fluid osmolality maintenance, Blood pressure / volume homeostasis, Action potential depolarization (voltage-gated Na+ channels), SGLT1 glucose cotransport Methionine synthase cofactor, Methylmalonyl-CoA mutase cofactor, Myelin integrity, Erythropoiesis
Deficiency Condition
Hyponatremia (Serum Na+ < 135 mmol/L): Cerebral edema, Nausea, Muscle cramps, Seizures, Coma (often exercise-associated from over-hydration) Pernicious / Megaloblastic Anemia, Irreversible Neurological Peripheral Neuropathy
Top Whole Food Sources
Table Salt (NaCl), Cured Bacon, Soy Sauce, Parmigiano-Reggiano, Pickles, Olives, Bread (Processed food accounts for 70% of intake) Oysters, Beef Liver, Sardines, Salmon, Beef, Dairy, Eggs (Absent in unfortified plant foods)
Adult Adequate Intake (AI)
1,500 mg / day (Equal to 3.8 g table salt NaCl)
Chronic Disease Limit (CDRR)
2,300 mg / day (Equal to 5.8 g table salt / 1 level teaspoon)
Renal Renin-Angiotensin System
Juxtaglomerular apparatus senses low tubular sodium/pressure, secreting renin to stimulate aldosterone and renal Na+ reabsorption
Adult RDA / RDI
2.4 µg / day (2.6µg pregnancy, 2.8µg lactation)
Tolerable Upper Limit (UL)
None Established (Extremely low toxicity)
Absorption Mechanism
Requires Gastric Acid, R-Protein, and Intrinsic Factor (IF) via Ileal Cubam receptors