Dietary sources of vitamin K include kale, spinach, broccoli, and other leafy greens. Some dairy foods also contain vitamin K.
The investigators who carried out the study say that their findings "suggest vitamin K may be involved in the disablement process in older age."
They describe their work in a paper that features in a recent issue of The Journals of Gerontology: Series A.
Previous studies have established links between vitamin K and long-term conditions that can raise the risk of mobility disability. These conditions include cardiovascular disease and osteoarthritis.
However, none of those earlier investigations had examined the relationship between vitamin K and mobility disability directly.
M. Kyla Shea is the new study's first and corresponding author. She researches Vitamin K at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston, MA.
Shea explains that: "Low vitamin K status has been associated with the onset of chronic diseases that lead to disability, but the work to understand this connection is in its infancy."
She and her colleagues believe that they are the first to evaluate the relationship between "vitamin K status and incident mobility disability" in older adults.
The new evidence builds on earlier studies that have associated low levels of circulating vitamin K with "slower gait speed and a higher risk of osteoarthritis," Shea explains.
Mobility is fundamental to healthy aging
Researchers typically define mobility as the "ability to move independently" from one place to another.
Physical independence is integral to healthy aging and older adults' quality of life. From being able to get out of bed to walking and climbing stairs, much of daily activities involve mobility.
