Vitamin K – Food Sources, Benefits, Dosage


Vitamin K comes from three sources: plants, the human intestine, and artificial sources. The most efficient, and effective, is vitamin K2, also known as menaquinone. Produced by gut bacteria, this form is supplied directly to blood vessels, bones, and tissues.

Foods rich in vitamin K include cruciferous vegetables like broccoli and Brussels sprouts; kale and spinach; and many “greens” (i.e., turnip greens, mustard greens, beet greens, and dandelion greens). This vitamin is found in onions and green tea, but is also available, in abundance, from fermented foods like sauerkraut, cheese, natto, kimchi, kefir, kombucha, and tempeh. One American favorite is “seed cheese”, a tangy, cultured vegan cheese made from whey and various nuts or seeds, all high in vitamin K.

Vitamin K is a relatively recent addition to the list of vitamins and minerals essential to human health. Known as the “forgotten vitamin” because its role is so often ignored, this vitamin is essential in building strong bones; preventing heart disease; promoting brain health; and preventing cancer. This vitamin is also said to prevent tooth decay and certain dangerous infections like pneumonia. In fact, recent studies suggest that – if not a confirmed treatment for rheumatoid arthritis (RA) – vitamin K levels in the body may indicate the best treatments for RA amongst elderly patients prone to fragility fractures.

According to at least one source, this vitamin is dependent on vitamin D, and the lack of one means a deficiency in the other. Moreover, since getting enough of this vitamin through diet alone is difficult, if not impossible, in today’s vitamin-depleted-soil world, supplements are available.

Vitamin K deficiencies can strike any demographic and age group, but are most often found among the unborn or newly born, as hemorrhagic disease. This is because this vitamin does not cross the placenta, is not abundant in breast milk, and the gut bacteria needed for its synthesis are absent before a certain age.

This vitamin can be stored in the body for about a week. There is also one precaution about this vitamin. That is, since this vitamin interferes with the effectiveness of blood thinners like warfarin, people taking Coumadin or Jantoven should avoid excess amounts of vitamin K-rich foods or vitamin K supplements.