A new multiethnic study found that older adults with low vitamin K levels were more likely to die within 13 years compared with those whose vitamin K levels were adequate. The results suggest vitamin K may have protective health benefits as we age, according to the researchers.
The meta-analysis involved nearly 4,000 adults aged 54 to 76 who were categorized according to their vitamin K blood levels. They then compared risk of heart disease and risk of death across the categories over nearly 13 years of follow-up.
Although the results showed no significant associations between vitamin K levels and heart disease, those with the lowest vitamin K levels had a 19% higher risk of death compared with those with adequate vitamin K status.
“The possibility that vitamin K is linked to heart disease and mortality is based on our knowledge about proteins in vascular tissue that require vitamin K to function. These proteins help prevent calcium from building up in artery walls, and without enough vitamin K, they’re less functional,” explained lead author Kyla Shea, PhD.
“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’s why measuring risk of death, in a study such as this, may better capture the spectrum of events associated with worsening vascular health,” said last author Daniel Weiner, MD.
The meta-analysis combined data from participants in three ongoing studies: the Health, Aging, and Body Composition Study, the Multi-Ethnic Study of Atherosclerosis, and the Framingham Heart Study (Offspring Cohort). Vitamin K levels for participants in all three studies were measured after fasting, with the same test, and processed at the same laboratory (the vitamin K laboratory at the USDA HNRCA), minimizing the potential for laboratory-based variation. The test showed levels of circulating phylloquinone, the compound known as vitamin K1.