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

Magnesium (Elemental Mg) vs. Vitamin B12 (Cobalamin)

Comparing 2 standards across 9 specifications. 9 key differences identified.

Comparing:
Magnesium (Elemental Mg)
Vitamin B12 (Cobalamin)
Magnesium (Elemental Mg) →

Magnesium is an essential macromineral required as an enzymatic cofactor in over 300 biochemical reactions including ATP synthesis, DNA replication, and neuromuscular transmission. Adult RDA is 400–420mg (men) / 310–320mg (women).

View full Magnesium (Elemental Mg) spec sheet →
Vitamin B12 (Cobalamin) →

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

9 Parameters
Parameter / Spec
Magnesium (Elemental Mg)
Vitamin B12 (Cobalamin)
Nutrient Type
Essential Macromineral Water-Soluble Corrinoid Vitamin
Adult RDA / RDI
400 – 420 mg / day (Men) / 310 – 320 mg / day (Women) 2.4 µg / day (2.6µg pregnancy, 2.8µg lactation)
Tolerable Upper Limit (UL)
350 mg / day (From supplemental forms only; no limit on whole foods) None Established (Extremely low toxicity)
Chemical Forms
Magnesium Glycinate (Chelate), Citrate, Malate, Oxide, L-Threonate Methylcobalamin (Active), Adenosylcobalamin (Active), Cyanocobalamin (Stable synthetic)
Primary Biological Function
Mg-ATP complex cofactor (>300 enzymes), NMDA receptor gatekeeper, Protein synthesis, Muscle relaxation Methionine synthase cofactor, Methylmalonyl-CoA mutase cofactor, Myelin integrity, Erythropoiesis
Deficiency Condition
Muscle cramps, Tremors, Ventricular arrhythmias, Insulin resistance, Insomnia Pernicious / Megaloblastic Anemia, Irreversible Neurological Peripheral Neuropathy
Top Whole Food Sources
Pumpkin Seeds, Hemp Hearts, Chia Seeds, Almonds, Spinach, Black Beans, Dark Chocolate Oysters, Beef Liver, Sardines, Salmon, Beef, Dairy, Eggs (Absent in unfortified plant foods)
Cellular Distribution
99% intracellular (60% bone, 39% skeletal muscle, <1% serum) —
Absorption Mechanism
— Requires Gastric Acid, R-Protein, and Intrinsic Factor (IF) via Ileal Cubam receptors

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