Comparison
Glutathione vs Vitamin D3 + K2
Side-by-side of Glutathione and Vitamin D3 + K2. Every row below is pulled from the compound schema and will update as our data grows. For deeper reads, follow through to each compound page.
Glutathione
Glutathione (GSH) is the body's primary intracellular antioxidant. Oral supplementation has variable bioavailability; sublingual, liposomal, and IV forms.
Vitamin D3 + K2
Vitamin D3 K2 supplement profile: cholecalciferol at 1000-4000 IU/day corrects deficiency, MK-7 directs calcium to bone, away from arteries.
Effects at a glance
Glutathione
- •Body's primary intracellular antioxidant; tripeptide of glutamate, cysteine, glycine
- •Oral bioavailability poor; sublingual, liposomal, IV more reliable
- •Richie 2014 trial showed body GSH store increases at 250-1000 mg/day for 6 months
- •NAC supplementation often more cost-effective indirect strategy
- •Modest signals in NAFLD, skin aging, immune support; weak in cardiovascular
Vitamin D3 + K2
- •Reduces non-vertebral fractures 10-20% in older adults at 800 IU/day or above when combined with calcium
- •VITAL trial showed neutral results on primary CV and cancer endpoints at 2000 IU/day over 5 years
- •Vitamin D supplementation reduces respiratory infection incidence ~10-20% in deficient populations
- •K2 MK-7 has 72-hour plasma half-life vs 1-2 hours for MK-4; once-daily dosing is sufficient
- •Synergy hypothesis is largely preclinical; dedicated combination RCTs are limited
- •Daily dosing outperforms bolus dosing for immune and infection outcomes
Side-by-side
| Attribute | Glutathione | Vitamin D3 + K2 |
|---|---|---|
| Category | supplement | supplement |
| Also known as | GSH, L-glutathione, reduced glutathione | cholecalciferol + menaquinone, D3/K2, vitamin D3 with MK-7 |
| Half-life (hr) ↗ | 0.5 | 360 |
| Typical dose (mg) ↗ | 500 | 0.05 |
| Dosing frequency | daily, often divided | daily with a fat-containing meal |
| Routes | oral, sublingual, intravenous | oral |
| Onset (hr) | 1 | 24 |
| Peak (hr) | 2 | 168 |
| Molecular weight | 307.32 | 384.64 |
| Molecular formula | C10H17N3O6S | C27H44O (D3); C46H64O2 (MK-7) |
| Mechanism | Tripeptide antioxidant; substrate for glutathione peroxidase (H2O2 reduction), GST (xenobiotic conjugation), glutaredoxin (redox signaling). GSH:GSSG ratio is the central cellular redox indicator. | D3 converts to calcidiol then calcitriol, activating the vitamin D receptor (VDR) to increase intestinal calcium absorption and modulate immune and bone gene transcription. K2 carboxylates osteocalcin and matrix Gla protein, directing calcium toward bone and inhibiting vascular calcification. |
| Legal status | OTC dietary supplement | Dietary supplement (global) |
| WADA status | allowed | allowed |
| DEA / Rx | OTC supplement | Not scheduled |
| Pregnancy | Insufficient data at supplemental doses; endogenous compound is safe | Recommended at standard doses for fetal bone development; consult clinician at higher doses |
| CAS | 70-18-8 | 67-97-0 |
| PubChem CID | 124886 | 5280795 |
| Wikidata | Q116907 | Q139347 |
Safety profile
Glutathione
Common side effects
- mild GI upset
Contraindications
- asthma (IV / inhaled forms specifically)
- active chemotherapy without oncologist guidance
Interactions
- chemotherapy agents: theoretical interference with GSH-depletion-dependent agents(moderate)
Vitamin D3 + K2
Common side effects
- GI upset at high doses
- headache (rare)
- hypercalcemia (only at sustained very high D3 doses)
Contraindications
- hypercalcemia
- sarcoidosis
- active hyperparathyroidism
- warfarin therapy (K2 component requires stable intake)
Interactions
- warfarin: K2 component can affect anticoagulation; maintain stable intake and inform anticoagulation clinic(moderate)
- thiazide diuretics: additive calcium retention; hypercalcemia risk with high-dose D3(moderate)
- digoxin and calcium channel blockers: additive effects from D3-induced hypercalcemia(moderate)
- glucocorticoids: reduced vitamin D efficacy and bone effects(moderate)
- cholestyramine and orlistat: bind fat-soluble vitamins; separate dosing by 2 to 4 hours(moderate)
Which Should You Take?
Vitamin D3 + K2 comes out ahead for most readers on the criteria we weight: 3 catalogued goals, OTC dietary supplement, oral dosing, with a Tier-A outcome catalogued. Glutathione is the right call when one of the conditionals below applies.
- → If your priority is liver function, pick Glutathione.
- → If your priority is immune support, pick Glutathione.
- → If your priority is bone density, pick Vitamin D3 + K2.
- → If your priority is cardiovascular health, pick Vitamin D3 + K2.
Edge case: Half-lives differ materially (Glutathione ~0.5 hr vs Vitamin D3 + K2 ~360 hr). Vitamin D3 + K2 reaches steady state faster; Glutathione is easier to dial in if tolerability is uncertain.
Default choice: Vitamin D3 + K2. Lower friction to source, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for Glutathione only if your priority sits squarely in the goals it owns above.
This verdict is generated from each compound's schema (goals, legal status, evidence outcomes, dosing route). It updates automatically as our compound data evolves; the deeper read sits on each individual compound page.
Common questions
What is the difference between Glutathione and Vitamin D3 + K2?
Glutathione and Vitamin D3 + K2 differ in category (supplement vs supplement), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Glutathione or Vitamin D3 + K2?
Glutathione half-life is 0.5 hours; Vitamin D3 + K2 half-life is 360 hours.
Can you stack Glutathione with Vitamin D3 + K2?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
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