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

Vitamin B1 (Thiamine) vs. Vitamin D3 (Cholecalciferol)

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

Comparing:
Vitamin B1 (Thiamine)
Vitamin D3 (Cholecalciferol)
Vitamin B1 (Thiamine) →

Vitamin B1 is a water-soluble pyrimidine/thiazole vitamin acting as the Thiamine Pyrophosphate (TPP) coenzyme in pyruvate dehydrogenase, alpha-ketoglutarate dehydrogenase, and transketolase. Adult RDA is 1.2 mg (men) / 1.1 mg (women) (no Upper Limit established).

View full Vitamin B1 (Thiamine) 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 B1 (Thiamine)
Vitamin D3 (Cholecalciferol)
Nutrient Type
Water-Soluble Thiazole Vitamin Fat-Soluble Secosteroid Prohormone
Adult RDA / RDI
1.2 mg / day (Men) / 1.1 mg / day (Women) (+0.3mg during pregnancy) 600 – 800 IU / day (15 – 20 µg)
Tolerable Upper Limit (UL)
None Established (Rapid renal clearance of excess) 4,000 IU / day (100 µg) (Endocrine Society: up to 10,000 IU safe)
Chemical Forms
Thiamine Monophosphate, Thiamine Pyrophosphate (TPP / TDP, active coenzyme), Benfotiamine (Lipid-soluble synthetic) Cholecalciferol (D3 - Animal/Lichen), Ergocalciferol (D2 - Fungi)
Primary Biological Function
Pyruvate dehydrogenase complex (Links glycolysis to Krebs cycle), Transketolase (Pentose Phosphate Pathway), Myelin neurotransmission Calcitriol receptor (VDR) activation, intestinal calcium/phosphorus absorption, antimicrobial peptide synthesis
Deficiency Condition
Beriberi (Wet beriberi: high-output heart failure; Dry beriberi: peripheral neuropathy), Wernicke-Korsakoff syndrome Rickets (children), Osteomalacia (adults), Immune dysregulation
Top Whole Food Sources
Pork Tenderloin, Sunflower Seeds, Nutritional Yeast, Enriched Grains, Black Beans, Flaxseeds Sunlight UVB, Atlantic Salmon, Sardines, Egg Yolk, Fortified Milk
Thermolability & Alcohol Interaction
Degraded by alkaline pH and high heat cooking; alcohol blocks intestinal active ThTr-1 transport —
Target Serum 25(OH)D Level
— 30 – 50 ng / mL (75 – 125 nmol / L)

Other Alternatives to Compare

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