Vitamin K deficiency can slow blood clotting and cause more blood to accumulate under the skin as a bruise.
Notes on verification
Well-established physiological mechanism corroborated by multiple independent clinical/medical references including MSD Manuals and peer-reviewed overviews.
Sources
- Random Bruising: 13 Possible Causes Excluding Obvious Injury (healthline.com)
- https://ada.com/conditions/vitamin-k-deficiency/ (ada.com)
- https://www.msdmanuals.com/professional/nutritional-disorders/vitamin-deficiency-dependency-and-toxicity/vitamin-k-deficiency (msdmanuals.com)
- https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/vitamin-k-deficiency (sciencedirect.com)
- https://www.healthdirect.gov.au/vitamin-k-deficiency (healthdirect.gov.au)