Older adults with low vitamin K levels are more likely to die within 13 years compared with those who have adequate vitamin K levels, according to a study published in The American Journal of Clinical Nutrition. 

Vitamin K is found in leafy greens and vegetable oils such as soybean and canola. It is important for maintaining healthy blood vessels and may also have protective health benefits, according to the study authors. 

The study, which was led by researchers at the Jean Mayer USDA Human Nutrition Center on Aging at Tufts University and Tufts Medical Center, was composed of nearly 4000 Americans between the ages of 54 and 76 years. The data were a meta-analysis of 3 different ongoing studies: The Health, Aging, and Body Composition Study, The Multi-Ethnic Study of Atherosclerosis, and the Framingham Heart Study. 

One-third of the study population was non-white and participants were categorized by vitamin K level, according to the press release. Over the course of approximately 13 years of follow-ups, researchers compared the risk of heart disease and risk of death among participants across the categories.    

Participants with the lowest vitamin K levels had a 19% higher risk of death compared with those with adequate vitamin K levels, according to the study; however, no significant association was found between heart disease and vitamin K levels. The relationship between vitamin K levels and death was observational, therefore, researchers were not able to firmly establish a connection. 

"Similar to when a rubber band dries out and loses its elasticity, when veins and arteries are calcified, blood pumps less efficiently, causing a variety of complications. That is why measuring risk of death, in a study such as this, may better capture the spectrum of events associated with worsening vascular health," last author and nephrologist at Tufts Medical Center, Daniel Weiner, MD, said in the press release. 

Additional studies are needed in order to clarify why vitamin K is associated with risk of death but not heart disease; however, this study adds to the growing body of evidence that vitamin K may have protective health benefits, according to the study authors. 

Reference:
Multi-ethnic study suggests vitamin K may offer protective health benefits in older age (News release), Middlesex County, MA, June 15, 2020, ScienceDaily, accessed July 28, 2020