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

Vitamin B2 (Riboflavin) vs. Vitamin D3 (Cholecalciferol)

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

Comparing:
Vitamin B2 (Riboflavin)
Vitamin D3 (Cholecalciferol)
Vitamin B2 (Riboflavin) →

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 D3 (Cholecalciferol) →

Vitamin D3 is a secosteroid prohormone synthesized endogenously in skin via solar UVB irradiation of 7-dehydrocholesterol. Adult RDA is 600–800 IU (15–20µg), with a Tolerable Upper Limit of 4,000 IU (100µg)/day, regulating systemic calcium absorption and immune gene expression.

View full Vitamin D3 (Cholecalciferol) spec sheet →

Specification Comparison Table

9 Parameters
Parameter / Spec
Vitamin B2 (Riboflavin)
Vitamin D3 (Cholecalciferol)
Nutrient Type
Water-Soluble Isoalloxazine Vitamin Fat-Soluble Secosteroid Prohormone
Adult RDA / RDI
1.3 mg / day (Men) / 1.1 mg / day (Women) 600 – 800 IU / day (15 – 20 µg)
Tolerable Upper Limit (UL)
None Established (Saturates intestinal absorption at ~27mg; excreted as harmless bright yellow urine) 4,000 IU / day (100 µg) (Endocrine Society: up to 10,000 IU safe)
Chemical Forms
Riboflavin, Riboflavin-5'-Phosphate (FMN), Flavin Adenine Dinucleotide (FAD) Cholecalciferol (D3 - Animal/Lichen), Ergocalciferol (D2 - Fungi)
Primary Biological Function
Complex I and Complex II mitochondrial electron transport chain cytochromes, Glutathione Reductase, B6/Folate activation Calcitriol receptor (VDR) activation, intestinal calcium/phosphorus absorption, antimicrobial peptide synthesis
Deficiency Condition
Ariboflavinosis (Angular cheilitis / cracked lip corners, glossitis / magenta tongue, seborrheic dermatitis) Rickets (children), Osteomalacia (adults), Immune dysregulation
Top Whole Food Sources
Beef Liver, Dairy Milk, Greek Yogurt, Eggs, Almonds, Portobello Mushrooms, Spinach Sunlight UVB, Atlantic Salmon, Sardines, Egg Yolk, Fortified Milk
Photodegradation Vulnerability
Extremely light-sensitive (dairy milk stored in clear glass loses 50% riboflavin within 2 hours of sunlight exposure) —
Target Serum 25(OH)D Level
— 30 – 50 ng / mL (75 – 125 nmol / L)

Other Alternatives to Compare

Compare Vitamin B2 (Riboflavin) vs. Calcium (Elemental Ca) → Compare Vitamin B2 (Riboflavin) vs. Iodine (Elemental I) → Compare Vitamin B2 (Riboflavin) vs. Iron (Heme & Non-Heme) → Compare Vitamin B2 (Riboflavin) vs. Magnesium (Elemental Mg) → Compare Vitamin B2 (Riboflavin) vs. Potassium (Elemental K) → Compare Vitamin B2 (Riboflavin) vs. Selenium (Elemental Se) → Compare Vitamin B2 (Riboflavin) vs. Sodium (Elemental Na) → Compare Vitamin B2 (Riboflavin) vs. Vitamin A (Retinol & Beta-Carotene) → Compare Vitamin B2 (Riboflavin) vs. Vitamin B1 (Thiamine) → Compare Vitamin B2 (Riboflavin) vs. Vitamin B12 (Cobalamin) → Compare Vitamin B2 (Riboflavin) vs. Vitamin B3 (Niacin / Nicotinic Acid & Nicotinamide) → Compare Vitamin B2 (Riboflavin) vs. Vitamin B5 (Pantothenic Acid) → Compare Vitamin B2 (Riboflavin) vs. Vitamin B6 (Pyridoxal 5'-Phosphate / PLP) → Compare Vitamin B2 (Riboflavin) vs. Vitamin B7 (Biotin / Vitamin H) → Compare Vitamin B2 (Riboflavin) vs. Vitamin B9 (Folate & Folic Acid) → Compare Vitamin B2 (Riboflavin) vs. Vitamin C (L-Ascorbic Acid) → Compare Vitamin B2 (Riboflavin) vs. Vitamin E (d-Alpha-Tocopherol) → Compare Vitamin B2 (Riboflavin) vs. Vitamin K1 (Phylloquinone) → Compare Vitamin B2 (Riboflavin) vs. Zinc (Elemental Zn) →