Vitamin D3 vs Vitamin E (Mixed Tocopherols/Tocotrienols)

Mechanism

Vitamin D3 (cholecalciferol) is hydroxylated in the liver to 25(OH)D (calcidiol), then in the kidneys to 1,25(OH)2D (calcitriol), the active hormone. Calcitriol binds the nuclear vitamin D receptor (VDR), forming a heterodimer with RXR that regulates >1000 genes. Key actions: upregulation of intestinal calcium/phosphorus absorption (TRPV6, calbindin), modulation of innate immunity (cathelicidin LL-37 antimicrobial peptide production), suppression of adaptive immune overactivation (Th1/Th17 to Treg shift), regulation of PTH and osteocalcin for bone mineralization, and modulation of insulin secretion from beta cells.

Standard Dosing

5000 IU daily (125 mcg)

Timing

With largest fat-containing meal of the day (fat-soluble). Morning preferred.

Cycle Duration

ongoing (lifelong for most people in northern latitudes)

Side Effects

• Hypercalcemia at excessive doses (>10,000 IU/day long-term without monitoring)
• Nausea/vomiting (toxicity)
• Kidney stones (with excessive calcium)
• Metallic taste (toxicity sign)

Contraindications

• Hypercalcemia
• Granulomatous diseases (sarcoidosis, some lymphomas — unregulated 1-alpha hydroxylase conversion)
• Primary hyperparathyroidism (without monitoring)
• Williams syndrome

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Mechanism

Vitamin E family comprises 4 tocopherols (alpha, beta, gamma, delta) and 4 tocotrienols. Alpha-tocopherol is the primary lipid-soluble, chain-breaking antioxidant in cell membranes, intercepting peroxyl radicals to halt lipid peroxidation. Gamma-tocopherol uniquely traps reactive nitrogen species (peroxynitrite). Tocotrienols have additional properties: inhibition of HMG-CoA reductase (cholesterol lowering), NF-kB suppression, induction of apoptosis in cancer cells, and neuroprotection. The full spectrum provides synergistic antioxidant, anti-inflammatory, and cell signaling functions.

Standard Dosing

200-400 IU mixed tocopherols + 50-100mg tocotrienols daily

Timing

With fat-containing meal.

Cycle Duration

ongoing

Side Effects

• GI upset at high doses
• Fatigue
• Headache
• Blurred vision (rare)
• Increased all-cause mortality signal at >400 IU synthetic dl-alpha-tocopherol in meta-analyses

Contraindications

• Vitamin K deficiency or warfarin therapy (at high doses)
• Scheduled surgery (discontinue 2 weeks prior at >400 IU)
• Retinitis pigmentosa (alpha-tocopherol contraindicated in some forms)

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