Science Update

New study demonstrates the importance of vitamin K and cardiovascular function in teens


According to a new study published this past Sunday in The Journal of Nutrition researchers demonstrated that there is a 3.3 times greater risk of heart enlargement in healthy teens who consumed the least amount of vitamin K1. This is the form of vitamin K predominantly found in green leafy vegetables such as spinach cabbage and lettuce. Vitamin K plays a significant role in blood clotting cardiovascular health and optimal bone health. It is essential for the production of osteocalcin.

Interestingly approximately 10% of the teens had some degree of left ventricular hypertrophy according to the research team. This is the first study exploring associations between vitamin K and heart function and structure in young healthy individuals. These results suggest early interventions to ensure adequate vitamin K1 in young people could improve cardiovascular development as well as reduce future cardiovascular disease risk.

This study consisted of 766 teens 14 to 18 years of age. They found that those who consumed the least amount of vitamin K1 had an increased overall size and thickness of the left ventricle. Only 1/4 of the teens met the current adequate intake levels of the Food and Nutrition Board of the Institute of Medicine. (According to the researchers there is also evidence emerging that vitamin K levels are lower in obese and overweight children.)

Interestingly the Framingham Offspring Cohort Study also found an association between higher vitamin K1 levels and lower lipid levels in the blood.

Vitamin K requirements should be met with a combined intake of K1 from food sources and supplementation since some K1 will convert to K2-MK-4. There has been a lot of hype and promotion of K2 (MK-7) but keep in mind there are no proprietary forms of K1 and K2 (MK-4). Vitamin K2 as MK-7 does convert to K2 as MK-4. There is also no evidence for an ideal ratio between D and K1 or K2. The bottom line is that we need to optimize each of these based on testing.

I find that most people need anywhere from 5000-10000 IUs/day of vitamin D and about 1-2 mg of K1 since most people do not eat enough vegetables (as seen in this study) to get enough K from diet alone. This is also the amount that carboxylates osteocalcin.

Approximately 70% of my patients have vitamin K insufficiencies. It seems to be as prevalent as magnesium deficiencies. As a general rule of thumb I never recommend vitamin D without vitamin K. In addition I have personally have found vitamin K1 supplementation to be much more successful at lowering undercarboxylated osteocalcin levels than K2 (MK-7). It makes sense to supplement with all three forms of vitamin K [K1 K2(MK-4 and MK-7)] and not get hung up on the marketing hype of one proprietary form.

By Michael Jurgelewicz DC DACBN DCBCN CNS

Source: Mary K Douthit Mary Ellen Fain Joshua T Nguyen Celestine F Williams Allison H Jasti Bernard Gutin Norman K Pollock. Phylloquinone Intake Is Associated with Cardiac Structure and Function in Adolescents. The Journal of Nutrition 2017; jn253666 DOI: 10.3945/jn.117.253666