The clearest current human evidence suggests a likely benefit for Bone density / bone health support. Claims should stay limited to the graded outcomes shown below.
Each row is a different health effect. A means the support looks strongest, B likely helpful, C mixed or modest, and — not enough human evidence yet.
Papers are individual studies. Research reviews summarize evidence from multiple studies, such as systematic reviews and meta-analyses.
Safety is graded separately from benefits. Even with a favorable safety label, these notes still matter if you take medication, are pregnant, or have a medical condition.
A quick read on what this page supports right now.
Products that pass third-party quality testing.
Product quality data coming soon
Any future product listings should stay aligned with the specific graded outcomes and the separate safety rows shown here.
This page shows the current public rows for Vitamin K / K2: 27 unique research papers across 1 visible health effect. Safety rows are shown separately from benefit rows when available. The page includes 16 review-level papers and 11 direct human study. Each supplement is graded by health effect using a certainty × effect matrix applied across PubMed evidence per health effect. Cochrane reviews and high-quality systematic reviews carry the most weight. See Methodology for full detail.
Read the full methodology → · Citation PDF coming soon