Comparison
Nicotinamide Riboside vs Vitamin D3 + K2
Side-by-side of Nicotinamide Riboside 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.
Nicotinamide Riboside
Nicotinamide riboside (NR) is the most-studied NAD+ precursor in humans. Sold as Niagen by Chromadex; raises plasma NAD+ 30-60% at 250-1,000 mg/day.
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
Nicotinamide Riboside
- •Most-studied NAD+ precursor in human trials; the original Niagen formulation by Chromadex
- •Plasma NAD+ rises 30-60% at 250-1,000 mg/day across multiple human PK trials
- •Martens 2018 reported reduced BP and arterial stiffness at 500 mg/day for 6 weeks
- •Dollerup 2018 found no insulin sensitivity change despite plasma NAD+ rise
- •Tissue NAD+ rise inconsistent; hard clinical endpoints not yet measured
- •Larger human safety database than NMN; comparable mechanistic effects
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 | Nicotinamide Riboside | Vitamin D3 + K2 |
|---|---|---|
| Category | supplement | supplement |
| Also known as | NR, Niagen, nicotinamide riboside chloride | cholecalciferol + menaquinone, D3/K2, vitamin D3 with MK-7 |
| Half-life (hr) ↗ | 8 | 360 |
| Typical dose (mg) ↗ | 500 | 0.05 |
| Dosing frequency | daily, typically morning | daily with a fat-containing meal |
| Routes | oral | oral |
| Onset (hr) | 1 | 24 |
| Peak (hr) | 4 | 168 |
| Molecular weight | 255.25 | 384.64 |
| Molecular formula | C11H15N2O5 | C27H44O (D3); C46H64O2 (MK-7) |
| Mechanism | NAD+ precursor via salvage pathway. Phosphorylated to NMN by nicotinamide riboside kinase (NRK), then converted to NAD+. Substrate for sirtuins, PARPs, and CD38. | 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 supplement doses | Recommended at standard doses for fetal bone development; consult clinician at higher doses |
| CAS | 1341-23-7 | 67-97-0 |
| PubChem CID | 439924 | 5280795 |
| Wikidata | Q3343054 | Q139347 |
Safety profile
Nicotinamide Riboside
Common side effects
- mild GI upset (rare)
- headache (rare)
Contraindications
- pregnancy / lactation (insufficient data)
- active cancer (theoretical, no contraindicating data)
Interactions
- pterostilbene: complementary sirtuin pathway (Basis combination)(minor)
- TMG (trimethylglycine): methylation support during high NAD+ precursor dosing(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?
Nicotinamide Riboside and Vitamin D3 + K2 score evenly on the criteria we weight (goal breadth, legal accessibility, evidence depth). The conditionals below should drive the decision more than any aggregate score.
- → If your priority is energy and stamina, pick Nicotinamide Riboside.
- → If your priority is metabolic health and glucose control, pick Nicotinamide Riboside.
- → 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 (Nicotinamide Riboside ~8 hr vs Vitamin D3 + K2 ~360 hr). Vitamin D3 + K2 reaches steady state faster; Nicotinamide Riboside is easier to dial in if tolerability is uncertain.
Default choice: either is defensible. Nicotinamide Riboside edges out on goal breadth + legal accessibility; Vitamin D3 + K2 is the right call if your priority sits in the goals listed 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 Nicotinamide Riboside and Vitamin D3 + K2?
Nicotinamide Riboside 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, Nicotinamide Riboside or Vitamin D3 + K2?
Nicotinamide Riboside half-life is 8 hours; Vitamin D3 + K2 half-life is 360 hours.
Can you stack Nicotinamide Riboside 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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