Vitamin B7 (Biotin / Vitamin H) vs. Vitamin E (d-Alpha-Tocopherol)
Comparing 2 standards across 10 specifications. 10 key differences identified.
Vitamin B7 is an essential sulfur-containing water-soluble vitamin serving as a prosthetic group for five carboxylase enzymes in gluconeogenesis, lipogenesis, and branched-chain amino acid catabolism. Adequate Intake (AI) is 30 µg/day (no Upper Limit established).
Vitamin E is the principal fat-soluble peroxyl radical-scavenging antioxidant protecting cellular polyunsaturated membrane phospholipids. Adult RDA is 15 mg (22.4 IU) of d-alpha-tocopherol, with a Tolerable Upper Limit of 1,000 mg (1,500 IU)/day.
Specification Comparison Table
10 Parameters| Parameter / Spec | ||
|---|---|---|
|
Nutrient Type
|
Water-Soluble Ureido-Tetrahydrothiophene Vitamin | Fat-Soluble Chromanol Lipophilic Vitamin |
|
Tolerable Upper Limit (UL)
|
None Established (No adverse effects recorded) | 1,000 mg / day (1,500 IU synthetic) (Excess impairs Vitamin K clotting cascade) |
|
Chemical Forms
|
D-Biotin (Biologically active isomer), Biocytin (Biotinyl-lysine) | RRR-alpha-Tocopherol (Natural d-alpha), all-rac-alpha-Tocopherol (Synthetic dl-alpha), Gamma/Delta-Tocopherols |
|
Primary Biological Function
|
Prosthetic group for Pyruvate Carboxylase (Gluconeogenesis), Acetyl-CoA Carboxylase (Fatty acid synthesis), Propionyl-CoA Carboxylase, Histone biotinylation | Breaks lipid peroxidation chain in PUFA cell membranes, protects LDL from oxidative modification, maintains erythrocyte membrane integrity |
|
Deficiency Condition
|
Alopecia (Hair loss), Erythematous scaly periorofacial rash, Brittle nails, Neurological depression / hallucinations | Hemolytic anemia, Spinocerebellar ataxia, Peripheral neuropathy, Loss of vibratory/proprioceptive sense |
|
Top Whole Food Sources
|
Egg Yolk, Beef Liver, Salmon, Pork Chop, Sunflower Seeds, Almonds, Sweet Potatoes | Wheat Germ Oil, Sunflower Seeds, Raw Almonds, Hazelnuts, Sunflower Oil, Spinach, Hass Avocado |
|
Adult Adequate Intake (AI)
|
30 µg / day (35 µg during lactation) | — |
|
Raw Egg White (Avidin) Interaction
|
Raw egg albumen contains avidin glycoprotein which binds biotin with Kd ~10^-15 M (the strongest non-covalent bond known), completely blocking absorption unless cooked | — |
|
Adult RDA / RDI
|
— | 15 mg / day (22.4 IU) of 2R-alpha-tocopherol |
|
Hepatic Alpha-TTP Specificity
|
— | The liver secretes only alpha-tocopherol into VLDL via Alpha-Tocopherol Transfer Protein (alpha-TTP); other tocopherols are degraded in bile |