News Stories

Press Stories

Finding New Health Benefits for Vitamin K

Study links vitamin K levels to longevity

Vitamin K, once thought important primarily for blood clotting, may have a much wider array of health benefits. One recent Spanish study reported that people with the highest dietary intake of vitamin K were at significantly lower risk of mortality from cardiovascular disease, cancer and all causes. And if you're not already consuming plenty of vitamin K—found in dark leafy greens, broccoli, Brussels sprouts and other vegetables (see box)—it's not too late to start: The study also found that people who increased their vitamin K intake were at lower mortality risk.

"This finding comes from the PREDIMED study," notes Health & Nutrition Letter editor Irwin H. Rosenberg, MD, "an important and authoritative trial in multiple European centers, which also supports the healthful benefits of the Mediterranean-style diet."

Publishing their findings in The Journal of Nutrition, researchers looked at data on 7,216 participants in the PREDIMED study who were at high risk of cardiovascular disease.

Participants completed detailed annual food questionnaires, from which their consumption of the different types of vitamin K was calculated. As an observational study, the research could identify associations but was not designed to prove cause and effect.

Over an average follow-up period of almost five years, participants with the highest intake of the most common dietary form of vitamin K (phylloquinone, sometimes called vitamin K1) were 46% less likely to die of cancer and 36% less likely to die from any cause than those with the lowest intake. Those who increased their phylloquinone intake were at 48% lower risk of cardiovascular mortality, 36% lower risk of cancer mortality, and 43% lower risk of all-cause mortality. Increasing intake of the other common form of vitamin K, menaquinone or vitamin K2, was also associated with reduced cancer and all-cause mortality risk, but not lower cardiovascular mortality.


KEY TO CLOTTING: First identified as an essential nutrient in 1935, vitamin K was initially recognized for its role in promoting blood clotting. In fact, the "K" in the vitamin's name comes from the German word for "coagulation vitamin," Koagulationsvitamin. Scientists discovered that vitamin K helps blood to clot by activating certain proteins that are made in the liver. More recent research has found that vitamin K may also activate several other important proteins in the body. Vitamin K's effect on blood clotting is why patients on blood thinners, such as warfarin (Coumadin), need to avoid fluctuations in their consumption of foods high in vitamin K. Suddenly boosting your intake of spinach, broccoli and similar foods could decrease the effectiveness of the medication, while cutting back on those vegetables could mean your dose is now too high.

"Blood thinners are among the top 15 drugs prescribed in this country," notes Sarah L. Booth, PhD, director of Tufts' HNRCA Vitamin K Laboratory "and adverse drug events for these drugs account for some staggering numbers among the elderly."

But being put on blood-thinning
medication doesn't mean you can never eat green vegetables again, she emphasizes: "Work with your healthcare provider to have green vegetables in your diet that contain healthy nutrients but may not have the high amount and variability in content of vitamin K that the greens listed have. Paler leaves and other green plant-based products, such as peas, are still healthy but are not so rich in vitamin K. Also, there are ways to have modest amounts of those high vitamin K greens in the diet, such as spinach, such as including some raw spinach in combination with other plant-based foods."

Vitamin K is also found in some green fruits, such as kiwis and green apples (especially the peels), but not in amounts that should be of concern to those on blood-thinning medication. Booth adds, however, "One popular food item that is appearing more often on grocery shelves that may be of concern is green seaweed, especially if consumed in large amounts."

BY THE NUMBERS: Much of what we know about the content of vitamin K in the US food supply comes from research conducted in Tufts' HNRCA Vitamin K Laboratory. Phylloquinone (1(1), found in leafy green and cruciferous vegetables, makes up about 90% of our dietary vitamin K. The body can also use K1 from the diet to synthesize menaquinone (K2), which takes several different forms. Menaquinone-4, for example, is found in most dairy products and poultry. Other types of K2 are found in fermented soybean products and fermented cheese.

The US Dietary Reference Intake (DRI) recommendation for vitamin K is 120 micrograms per day for men and 90 micrograms daily for women. True vitamin K deficiency—usually indicated by an inability of the blood to clot normally—is rare. But you still might not be getting enough vitamin K to enjoy its other, less well-studied health benefits: In a review of studies on vitamin K status among the elderly, Booth reported that although older adults seem to consume more vitamin K than younger adults, many seniors still aren't getting the recommended daily amount.

CARDIOVASCULAR BENEFITS: Tufts researchers have also conducted numerous studies to explore the possible benefits of vitamin K beyond its role in blood clotting. They have recently found, for example, that older adults who have existing calcification in their coronary arteries have less progression of calcification if they receive supplemental vitamin K in amounts attainable in the diet.

In another study, blood levels of phylloquinone were measured in 296 participants with extreme coronary artery calcification progression and 561 randomly selected participants without the condition. Although the data suggested that low K1 levels were associated with greater calcification progression, the difference was not statistically significant. Low K1 was significantly associated with coronary artery calcification progression in antihypertension medication users, however. Booth and colleagues concluded, "Intervention trials are needed to determine whether improving serum vitamin K1 reduces coronary artery calcification progression, especially in hypertensive individuals."

Previous Tufts research has linked blood levels and dietary intakes of K1 to inflammation, another factor in cardiovascular disease. Researchers who looked at data from 1,381 participants in the Framingham Offspring Study, average age 59, compared vitamin K levels to 14 different biological markers (biomarkers) of inflammation. As blood levels and intake rose, those biomarkers of inflammation fell.

More recently, researchers reported that people who have high concentrations of biomarkers of inflammation have poor vitamin K status. Chronic inflammation has also been associated with a range of conditions that include arthritis, Alzheimer's disease and cognitive decline, and type-2 diabetes. Vitamin K may also help prevent diabetes by affecting blood-sugar control: In a three-year study, older men who received vitamin K supplementation showed less progression of insulin resistance. And Tufts researchers have found that higher blood levels of vitamin K1 are associated with lower risk of osteoarthritis in the hand and knee.

BUILDING STRONGER BONES?: Scientists also continue to explore vitamin K's role in bone metabolism, which could be important to fighting osteoporosis and the fractures often associated with aging. One Japanese study, for example, compared dietary differences in various regions with data from a national survey on the incidence of hip fracture. Researchers found that people in areas where certain vitamin K-rich foods were consumed in abundance had fewer hip fractures. The opposite also proved true: People in regions where intake of vitamin K was lower had more fractures.

Another study, in the Netherlands, suggested that the menaquinone-4 form of vitamin K2 may help maintain bone strength in postmenopausal women, along with proven bone-boosters calcium and vitamin D. In the three-year study of 325 healthy older women, the researchers found that those taking daily supplements of menaquinone-4 maintained hipbone strength, while women on a placebo suffered weakening. While no benefit was seen for bone-mineral density, women in the menaquinone-4 group also showed better compression strength, bending strength, impact strength and femoral neck width than those in the placebo group.

Source- National Osteoporosis Foundation Website- the article comes from the Tufts Nutrition Newsletter detailing the emerging health benefits associated with vitamin K.

Prevention of Costly Hip Fractures Should be a Priority in UK

Hip fractures account for an estimated £1.1 billion in hospital costs annually; costs expected to increase dramatically with ageing of the population. A new study presented today at the World Congress on Osteoporosis, Osteoarthritis and Musculoskeletal Diseases reveals the high cost of first and subsequent hip fractures to the healthcare system in the UK. Researchers from the University of Oxford and the MRC Lifecourse Epidemiology Unit in Southampton estimated UK hospital costs of hip fracture in the two years following the fracture, and compared average hospital costs before and after hip fracture. Their study analyzed data from 33152 hip fracture patients (average age 83 years), 75% of which were women.

The study found that hospital costs after hip fracture were an average of £14,163 in the first year and £16,302 in the first two years following the incident. Having a hip fracture increased hospital costs by £10,964 compared to the year before the fracture. The study reports the main cost drivers in the first year following hip fracture to be experiencing a second hip fracture, hip fracture-related complications and breaking other bones. The study shows that hip fractures are an enormous cost to the healthcare system, with total annual hospital costs of new hip fractures estimated to be approximately £1.1 billion. Lead author, Dr. Jose Leal of the Health Economics Research Center, University of Oxford stated, "The impact of hip fractures is very significant. The UK population is ageing and unless action is taken to prioritize fracture prevention, the cost of treating fractures in the senior population will continue to rise dramatically in the future." He added, "To reduce the costs of fractures we need to identify and invest in cost-effective approaches and incentives aimed at preventing avoidable fractures and improving the quality of life in these elderly populations. Fracture liaison services in hospitals and clinics have been shown to be a way forward as approximately half of the patients who are treated in hospital for hip fracture - the most costly, serious and even life-threatening type of fractures - have had a previous fracture of some kind. That first fracture was a ‘warning' that should have triggered testing and treatment." Senior Author, Dr M K Javaid, NDORMS, University of Oxford, stated, "Given the number of hip fractures will more than double in some countries by in the next 30 years, the results of this study strengthens the case for policy makers to prioritize the bone health of the nation through the universal provision of Fracture Liaison Services."

Reference: Abstract OC36 Impact of hip fracture on hospital care costs: a population based study. J. Leal, A.M Gray, M.K. Javaid, et al. Osteoporosis International, Vol. 26, s 1. 2015

This article presents independent research funded by the National Institute for Health Research (NIHR). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health.

1. The National Institute for Health Research Health Services and Delivery Research (NIHR HS&DR) Programme was established to fund a broad range of research. It builds on the strengths and contributions of two NIHR research programmes: the Health Services Research (HSR) programme and the Service Delivery and Organisation (SDO) programme, which merged in January 2012. The programme aims to produce rigorous and relevant evidence on the quality, access and organisation of health services, including costs and outcomes. The programme will enhance the strategic focus on research that matters to the NHS. The HS&DR Programme is funded by the NIHR with specific contributions from the CSO in Scotland, NISCHR in Wales and the HSC R&D Division, Public Health Agency in Northern Ireland. 

2. The National Institute for Health Research (NIHR) is funded by the Department of Health to improve the health and wealth of the nation through research. Since its establishment in April 2006, the NIHR has transformed research in the NHS. It has increased the volume of applied health research for the benefit of patients and the public, driven faster translation of basic science discoveries into tangible benefits for patients and the economy, and developed and supported the people who conduct and contribute to applied health research. The NIHR plays a key role in the Government's strategy for economic growth, attracting investment by the life-sciences industries through its world-class infrastructure for health research. Together, the NIHR people, programmes, centres of excellence and systems represent the most integrated health research system in the world. For further information, visit the NIHR website.

Osteoporosis-Related Fractures in China Expected to Double by 2035

Fractures in China's elderly population represent a growing economic burden to the Chinese healthcare system: costs will rise from approximately USD 10 billion in 2010 to USD 25.4 billion in 2050. The results of the first study using a health economics model to project osteoporosis-related fractures and costs for the Chinese population, shows that the country's healthcare system will face a dramatic rise in costs over the next few decades. The study forecasts that the incidence and costs of osteoporotic fractures in China will double by 2035, with costs rising to approximately USD 25.58 billion by 2050. In the study, published in the journal Osteoporosis International, investigators from the University of Tasmania, Anhui Medical University and Nanjing Medical University estimated that in 2010 more than 2.3 million osteoporosis-related hip, clinical vertebral and wrist fractures occurred in the population aged 50 years and over. The cost to the Chinese healthcare system was estimated to be approximately USD 10 billion. Women accounted for 73 % of the total costs, sustaining approximately three times more fractures than men.

IOF estimates that by 2050 more than 50 % of all osteoporotic fractures will occur in Asia – and China will be the country which is most affected due to its large population of seniors. By 2050, the Chinese population is projected to decrease slightly to 1.3 billion, but those aged over 50 years will reach almost half (49%) of the total population. In addition, those aged 70 years or above are projected to rise from 81 million in 2013 to 132 million in 2025, reaching 263 million by 2050. This is the population group at highest risk of costly and debilitating hip fractures.

Reflecting this expected increase in the ageing population, the researchers projected that the annual incidence and costs of osteoporotic fractures will double by 2035. By 2050 the number of fractures is expected to increase to 5.93 million resulting in costs of approximately USD 25.58 billion.

Lei Si, lead investigator of the study, said, "With increasing life expectancy and a growing population of seniors aged over 70 years, there is no doubt that the burden of osteoporosis and related fractures will grow dramatically in China. Our study underlines the need for an urgent focus on fracture preventive strategies and resources to treat and care for elderly fracture patients in the future." Andrew Palmer, Professor of Health Economics, Menzies Institute for Medical Research, University of Tasmania added, "We have identified that osteoporosis fractures represent a huge and increasing cost to Chinese society. We now need to identify effective screening, prevention and treatment strategies that are good value for money in order to reduce the size of this problem. Our team has just finished developing a cutting edge tool to do this, and we will be working intensively to find the optimal screening and treatment strategies for China."

Reference: Projection of osteoporosis-related fractures and costs in China: 2010-2050
L.Si, T.M Winzenberg, Q Jiang, M. Chen, A.J. Palmer
Osteoporos Int (March 2015) DOI 10.1007/s00198-015-3093-2