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

Vitamin B12 (Cobalamin) vs. Vitamin K1 (Phylloquinone)

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

Comparing:
Vitamin B12 (Cobalamin)
Vitamin K1 (Phylloquinone)
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 →
Vitamin K1 (Phylloquinone) →

Vitamin K1 is a fat-soluble naphthoquinone synthesized by photosynthetic plants. Adequate Intake (AI) is 120µg (men) / 90µg (women), acting as an essential cofactor for gamma-glutamyl carboxylase in blood clotting and osteocalcin bone mineralization.

View full Vitamin K1 (Phylloquinone) spec sheet →

Specification Comparison Table

10 Parameters
Parameter / Spec
Vitamin B12 (Cobalamin)
Vitamin K1 (Phylloquinone)
Nutrient Type
Water-Soluble Corrinoid Vitamin Fat-Soluble Naphthoquinone Vitamin
Tolerable Upper Limit (UL)
None Established (Extremely low toxicity) None Established (No adverse effects reported)
Chemical Forms
Methylcobalamin (Active), Adenosylcobalamin (Active), Cyanocobalamin (Stable synthetic) Phylloquinone (K1 - Green Plants), Menaquinones (K2: MK-4, MK-7 - Ferments/Animal)
Primary Biological Function
Methionine synthase cofactor, Methylmalonyl-CoA mutase cofactor, Myelin integrity, Erythropoiesis Gamma-glutamyl carboxylase cofactor (Factors II, VII, IX, X), Osteocalcin carboxylation, Matrix Gla Protein (MGP) vascular calcification inhibitor
Deficiency Condition
Pernicious / Megaloblastic Anemia, Irreversible Neurological Peripheral Neuropathy Coagulopathy, Hemorrhage, Impaired bone density
Top Whole Food Sources
Oysters, Beef Liver, Sardines, Salmon, Beef, Dairy, Eggs (Absent in unfortified plant foods) Spinach, Kale, Broccoli, Brussels Sprouts, Natto (K2 MK-7), Parsley
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 —
Adult Adequate Intake (AI)
— 120 µg / day (Men) / 90 µg / day (Women)
Warfarin / Anticoagulant Interaction
— Direct competitive antagonist to Coumadin/Warfarin (requires consistent daily intake)

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