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

Vitamin B1 (Thiamine) vs. Vitamin B6 (Pyridoxal 5'-Phosphate / PLP)

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

Comparing:
Vitamin B1 (Thiamine)
Vitamin B6 (Pyridoxal 5'-Phosphate / PLP)

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 B6 is a water-soluble pyridine vitamin acting via its active coenzyme Pyridoxal 5'-Phosphate (PLP) in over 140 amino acid decarboxylation, transamination, and neurotransmitter synthesis reactions. Adult RDA is 1.3–1.7 mg, with a Tolerable Upper Limit of 100 mg/day.

View full Vitamin B6 (Pyridoxal 5'-Phosphate / PLP) spec sheet →

Specification Comparison Table

9 Parameters
Parameter / Spec
Nutrient Type
Water-Soluble Thiazole Vitamin Water-Soluble Pyridine Vitamin
Adult RDA / RDI
1.2 mg / day (Men) / 1.1 mg / day (Women) (+0.3mg during pregnancy) 1.3 mg / day (Adults 19–50) / 1.7 mg (Men 51+) / 1.5 mg (Women 51+)
Tolerable Upper Limit (UL)
None Established (Rapid renal clearance of excess) 100 mg / day (US FDA/NIH) / 12 mg / day (EFSA, revised down from 25mg in 2023) (Avoid sensory peripheral neuropathy)
Chemical Forms
Thiamine Monophosphate, Thiamine Pyrophosphate (TPP / TDP, active coenzyme), Benfotiamine (Lipid-soluble synthetic) Pyridoxal 5'-Phosphate (PLP, active coenzyme), Pyridoxine HCl, Pyridoxamine
Primary Biological Function
Pyruvate dehydrogenase complex (Links glycolysis to Krebs cycle), Transketolase (Pentose Phosphate Pathway), Myelin neurotransmission Transamination / deamination of amino acids, Serotonin / Dopamine / GABA synthesis from amino acids, Glycogen phosphorylase cofactor, Heme synthesis
Deficiency Condition
Beriberi (Wet beriberi: high-output heart failure; Dry beriberi: peripheral neuropathy), Wernicke-Korsakoff syndrome Microcytic sideroblastic anemia, Seborrheic dermatitis, Cheilosis, Peripheral neuropathy, Convulsions
Top Whole Food Sources
Pork Tenderloin, Sunflower Seeds, Nutritional Yeast, Enriched Grains, Black Beans, Flaxseeds Chickpeas, Wild Salmon, Yellowfin Tuna, Beef Liver, Chicken Breast, Russet Potatoes, Bananas
Thermolability & Alcohol Interaction
Degraded by alkaline pH and high heat cooking; alcohol blocks intestinal active ThTr-1 transport
Neurotoxicity Threshold
Chronic megadosing of Pyridoxine HCl (>200–500mg/day) causes reversible sensory neuropathy due to competitive inhibition of tissue PLP