Consumer Reports calls attention to the importance of vitamin K

06-Dec-2019 - Last updated on 06-Dec-2019 at 17:44 GMT

Many people – and older men in particular – are not getting enough vitamin K, says a new article by Consumer Reports that draws attention to the benefits of the vitamin.

The article, “Why You Need More Vitamin K”, appears in the December 2019 issue of Consumer Reports On Health. It can also be read online. The report highlights the health benefits of the vitamin for blood vessels, bones, and mobility, while also discussing the emerging potential for cognition.

“[A] 2015 study of people ages 65 and older, published in the journal Nutrients, found that those who consumed more vitamin K (207 micrograms or more per day from foods) performed better on cognition tests than their peers who ate less,” states the article.

K forms

Described by some as the “forgotten” vitamin, vitamin K comes in two main forms: Phylloquinone (vitamin K1) and menaquinones (vitamins K2).

K1 is found in green leafy vegetables such as lettuce, broccoli and spinach, and makes up about 90% of the vitamin K in a typical Western diet, while K2 makes up about 10% of Western vitamin K consumption and can be synthesized in the gut by the microflora.

Menaquinones (MK-n: with the n denoting the number of prenyl side chains) can also be found in the diet; MK-4 can be found in animal meat, MK-7, MK-8, and MK-9 are found in fermented food products like cheese, and natto, a fermented soybean paste, is a rich source of MK-7.

While most of the early work focused on bone health (and the majority of finished dietary supplements on the market are positioned for bones), the Rotterdam Study (published in 2004 in the Journal of Nutrition, Vol. 134, pp. 3100-3105) was one of the first to show that adequate intake of menaquinone was associated with less aortic calcification and a lower risk of all-cause mortality.

The wider benefits of vitamin K were also highlighted in a 2009 study by Joyce McCann, PhD, and Bruce Ames, PhD, from Children's Hospital Oakland Research Institute.

K1 vs K2

The Consumer Reports article does mention the two forms, but dismisses the importance of that difference.

“It’s more important to focus on getting enough of the vitamin than on the types,” it states, before including a quote from Sarah Booth, PhD, director of the Vitamin K Laboratory at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, who said the thought that K2 is superior is a “misconception”.

Commenting on this, Eric Anderson, SVP Global Marketing and Business Development at NattoPharma, which supplies the MenaQ7 branded vitamin K2, told us: “We are grateful for any and all positive discussions of Vitamin K2 in the media. With this article, however, it is unfortunate that it does not make a clearer distinction between Vitamins K1 and K2, particularly because there is an extensive body of research confirming that K2 delivers the bone and cardiovascular benefits that K1 cannot.

“We do not agree with Dr. Booth's comment that it is "misconception" that Vitamin K2 is the superior form -- the evidence is substantial confirming this; and while K1 is safe and plentiful in diets, it is not adequately converted to K2 in the body to positively impact bone or heart health.

“Further, there currently is no K2-specific recommended daily intake, making it even more difficult for the public to correct the epidemic state of K2 deficiency across the globe,” added Anderson. “But NattoPharma has been actively working to educate regulatory bodies that Vitamin K2’s separate and distinct mechanism of action requires its own RDI, and we continue this fight today.

“We are thrilled to report that discussions of Vitamin K2 have been increasing year over year in the media, leading to growing consumer, practitioner, and clinical community awareness. NattoPharma has actively informing the public about positive developments around Vitamin K2 research (whether driven by NP or not), and this has led to K2 now being a part of the media vernacular.”