Comparison
EGCG vs Vitamin D3 + K2
Side-by-side of EGCG 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.
EGCG
EGCG supplement guide: 300-600 mg/day green tea catechin for fat loss and cardiovascular markers. Hepatotoxicity risk above 800 mg/day fasted.
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
EGCG
- •Modest fat loss (~1.3 kg over 12 weeks) when combined with caffeine and caloric deficit
- •Small reductions in LDL cholesterol (3-6 mg/dL) and systolic blood pressure (2-3 mmHg)
- •EFSA flags hepatotoxicity risk above 800 mg/day, particularly when taken fasted
- •Bioavailability is 0.1-1.0%; gut microbiome variation drives population-variable response
- •Green tea extract typically combines EGCG with caffeine and L-theanine for additive effects
- •Reduces non-heme iron absorption when co-administered with meals
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 | EGCG | Vitamin D3 + K2 |
|---|---|---|
| Category | natural | supplement |
| Also known as | epigallocatechin gallate, green tea extract | cholecalciferol + menaquinone, D3/K2, vitamin D3 with MK-7 |
| Half-life (hr) ↗ | 3 | 360 |
| Typical dose (mg) ↗ | 400 | 0.05 |
| Dosing frequency | 1 to 2 times daily with food | daily with a fat-containing meal |
| Routes | oral | oral |
| Onset (hr) | 1.5 | 24 |
| Peak (hr) | 2 | 168 |
| Molecular weight | 458.37 | 384.64 |
| Molecular formula | C22H18O11 | C27H44O (D3); C46H64O2 (MK-7) |
| Mechanism | Inhibits catechol-O-methyltransferase (COMT) to prolong norepinephrine signaling; activates AMPK; scavenges reactive oxygen species via gallate ester; modulates gut microbiome and pancreatic lipase activity. | 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 | Dietary supplement; warning labels required above 800 mg/day in some EU jurisdictions | Dietary supplement (global) |
| WADA status | allowed | allowed |
| DEA / Rx | Not scheduled | Not scheduled |
| Pregnancy | Avoid high-dose extracts; moderate green tea consumption appears acceptable | Recommended at standard doses for fetal bone development; consult clinician at higher doses |
| CAS | 989-51-5 | 67-97-0 |
| PubChem CID | 65064 | 5280795 |
| Wikidata | Q307091 | Q139347 |
Safety profile
EGCG
Common side effects
- nausea
- abdominal discomfort
- diarrhea
- jitteriness (with caffeine)
- sleep disruption (with caffeine)
Contraindications
- pregnancy at high-dose extracts
- active liver disease
- iron deficiency anemia (separate dosing)
Interactions
- iron supplements: reduces non-heme iron absorption; separate by 2 to 3 hours(moderate)
- anticoagulants: additive effects at high catechin doses(minor)
- beta-blockers (nadolol): reduced absorption when taken simultaneously(moderate)
- hepatotoxic supplements (high-dose niacin, kava): theoretical additive hepatotoxicity at high EGCG doses(moderate)
- stimulants and caffeine: additive thermogenic and cardiovascular effects(minor)
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. EGCG is the right call when one of the conditionals below applies.
- → If your priority is metabolic health and glucose control, pick EGCG.
- → If your priority is bone density, pick Vitamin D3 + K2.
- → If your priority is healthspan extension, pick Vitamin D3 + K2.
Edge case: Half-lives differ materially (EGCG ~3 hr vs Vitamin D3 + K2 ~360 hr). Vitamin D3 + K2 reaches steady state faster; EGCG 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 EGCG 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 EGCG and Vitamin D3 + K2?
EGCG and Vitamin D3 + K2 differ in category (natural vs supplement), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, EGCG or Vitamin D3 + K2?
EGCG half-life is 3 hours; Vitamin D3 + K2 half-life is 360 hours.
Can you stack EGCG 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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