Vitamin B12 (Cobalamin) vs. Vitamin C (L-Ascorbic Acid)
Comparing 2 standards across 9 specifications. 9 key differences identified.
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.
Vitamin C is a water-soluble electron donor and antioxidant essential for collagen proline/lysine hydroxylation, non-heme iron absorption, and immune phagocyte function. Adult RDA is 90mg (men) / 75mg (women), with a Tolerable Upper Limit of 2,000mg/day.
Specification Comparison Table
9 Parameters| Parameter / Spec | ||
|---|---|---|
|
Nutrient Type
|
Water-Soluble Corrinoid Vitamin | Water-Soluble Vitamin |
|
Adult RDA / RDI
|
2.4 µg / day (2.6µg pregnancy, 2.8µg lactation) | 90 mg (Men) / 75 mg (Women) (+35mg for smokers) |
|
Tolerable Upper Limit (UL)
|
None Established (Extremely low toxicity) | 2,000 mg / day (Avoid osmotic diarrhea) |
|
Chemical Forms
|
Methylcobalamin (Active), Adenosylcobalamin (Active), Cyanocobalamin (Stable synthetic) | L-Ascorbic Acid, Sodium Ascorbate, Calcium Ascorbate |
|
Primary Biological Function
|
Methionine synthase cofactor, Methylmalonyl-CoA mutase cofactor, Myelin integrity, Erythropoiesis | Prolyl/Lysyl Hydroxylase cofactor (Collagen), ROS scavenger, Carnitine synthesis |
|
Deficiency Condition
|
Pernicious / Megaloblastic Anemia, Irreversible Neurological Peripheral Neuropathy | Scurvy (Collagen breakdown, capillary fragility, impaired wound healing) |
|
Top Whole Food Sources
|
Oysters, Beef Liver, Sardines, Salmon, Beef, Dairy, Eggs (Absent in unfortified plant foods) | Red Bell Pepper, Strawberries, Citrus, Kiwi, Broccoli, Brussels Sprouts |
|
Absorption Mechanism
|
Requires Gastric Acid, R-Protein, and Intrinsic Factor (IF) via Ileal Cubam receptors | — |
|
Thermolability
|
— | Highly heat- and oxygen-sensitive (degrades rapidly with prolonged boiling) |