Compare interventions

Use the same six evidence dimensions for both. This prevents a strong animal result for one product being compared with a human clinical result for another.

First intervention

versus

Second intervention

Vitamin and bone metabolism

Vitamin K2

Mostly indirect evidence

Biologically relevant to clotting and bone proteins; routine anti-calcification claims exceed the trial evidence.

Human clinical outcomes Preliminary

Human biomarkers Moderate

Animal lifespan None

Mechanistic plausibility Strong

Safety certainty Moderate

Direct longevity relevance Preliminary

Verdict: Vitamin K is essential for activation of proteins involved in blood clotting and bone metabolism. K2 forms are heavily marketed alongside vitamin D for bone and arterial health, but trials have not established a universal need for K2 supplementation or a reliable reduction in cardiovascular events, fractures or mortality in generally healthy adults.

Open full dossier

NAD+ precursor

NMN

Early human evidence

Raises NAD-related biomarkers; broad healthspan benefits have not followed reliably.

Human clinical outcomes Preliminary

Human biomarkers Moderate

Animal lifespan Limited

Mechanistic plausibility Moderate

Safety certainty Limited

Direct longevity relevance Preliminary

Verdict: Nicotinamide mononucleotide can raise NAD-related measures in humans, which confirms biological activity. Trials have reported selected metabolic or functional effects, but results are mixed, studies are generally short, and no human evidence shows slower ageing or longer life.

Open full dossier