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

Vitamin B2 (Riboflavin) vs. Vitamin K1 (Phylloquinone)

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

Comparing:
Vitamin B2 (Riboflavin)
Vitamin K1 (Phylloquinone)

Vitamin B2 is an essential water-soluble isoalloxazine vitamin serving as the core structural component of Flavin Mononucleotide (FMN) and Flavin Adenine Dinucleotide (FAD) coenzymes in cellular redox respiration. Adult RDA is 1.3 mg (men) / 1.1 mg (women).

View full Vitamin B2 (Riboflavin) spec sheet →

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
Nutrient Type
Water-Soluble Isoalloxazine Vitamin Fat-Soluble Naphthoquinone Vitamin
Tolerable Upper Limit (UL)
None Established (Saturates intestinal absorption at ~27mg; excreted as harmless bright yellow urine) None Established (No adverse effects reported)
Chemical Forms
Riboflavin, Riboflavin-5'-Phosphate (FMN), Flavin Adenine Dinucleotide (FAD) Phylloquinone (K1 - Green Plants), Menaquinones (K2: MK-4, MK-7 - Ferments/Animal)
Primary Biological Function
Complex I and Complex II mitochondrial electron transport chain cytochromes, Glutathione Reductase, B6/Folate activation Gamma-glutamyl carboxylase cofactor (Factors II, VII, IX, X), Osteocalcin carboxylation, Matrix Gla Protein (MGP) vascular calcification inhibitor
Deficiency Condition
Ariboflavinosis (Angular cheilitis / cracked lip corners, glossitis / magenta tongue, seborrheic dermatitis) Coagulopathy, Hemorrhage, Impaired bone density
Top Whole Food Sources
Beef Liver, Dairy Milk, Greek Yogurt, Eggs, Almonds, Portobello Mushrooms, Spinach Spinach, Kale, Broccoli, Brussels Sprouts, Natto (K2 MK-7), Parsley
Adult RDA / RDI
1.3 mg / day (Men) / 1.1 mg / day (Women)
Photodegradation Vulnerability
Extremely light-sensitive (dairy milk stored in clear glass loses 50% riboflavin within 2 hours of sunlight exposure)
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)