Every vitamin and mineral gets its day in the spotlight. Right now it is vitamin D. However, look for big things to come regarding vitamin K. Beyond its known role in bone health and blood clotting, we are now learning vitamin K could be a large player preventing chronic diseases such as heart disease, diabetes and brain health decline with age. In addition, National Health and Nutrition Education Surveys show over half of American men and just under half of all women do not get the daily recommended amount of this fat soluble vitamin.
The most common source of vitamin K in the diet is phylloquinone, or K-1, which is largely found in green leafy vegetables, but is also found in other foods such as cashews, avocado, blueberries, blackberries and lentils. You can also get vitamin K in the form of menaquinone, or K-2, from fermented foods including cheese, as well as chicken liver, meat and eggs. Your gut bacteria also produces a small amount of vitamin K-2.
Vitamin K-2 helps regulate calcification in a way that protects arteries from hardening, and therefore research is looking at how vitamin K-2 may protect us from cardiovascular disease. In addition, recent studies point to vitamin K’s role in regulating glucose metabolism and insulin sensitivity, which might mean that deficiency or insufficiency plays a role in the development of diabetes and metabolic syndrome.
Vitamin K may also play a role in brain health. Correlation studies on humans (including the Quebec Longitudinal Study) and animals show a relationship between decreased vitamin K intake over a lifetime and increased risk of early cognitive decline.
Vitamin K’s role in bone health is well known. It is a known mechanism that plays a role in helping make bone strong, even if it is not very dense. A study on postmenopausal women with osteopenia found that supplementing with 5 mg of vitamin K1 had no effect on bone mineral density, but it did lead to a decrease of fractures. It is not just bones that benefit from vitamin K; joints might also require vitamin K, thanks to its regulation of cartilage mineralization.
As of now, there is no simple, single biomarker to measure vitamin K levels. However, I predict that soon there will be changes as more and more research points to the important impact of vitamin K on health.
The best way to add vitamin K to your diet is to consume more green vegetables and fermented foods. Keeping your gut bacteria healthy can also help to provide some vitamin K, although the levels are small. The body needs both K-1 and K-2. Therefore, it is best to find ways to consume both varieties to boost your overall health and well-being and help prevent some of these chronic illnesses. For those on blood thinners and other medication, discuss the interaction of vitamin K and these medications with a doctor prior to increasing the levels of vitamin K in your diet to reduce the chance of any adverse effects.
Georgia Boley MS,RD,LD, is the owner of www.Tailorednutritionllc.com.