Focus On: Vitamin K

Learn more about this essential micronutrient.

What it is: Vitamin K is an essential micronutrient found in certain foods and nutritional supplements. The most common trait of this micronutrient is its blood clotting features. There are two basic forms, vitamin K1 and K2, but they differ only slightly.

[ Benefits ]

Both K1 and K2 help promote healthy blood clotting and support brain and nervous-system structure. K2 is an important vitamin-D cofactor, ensuring that the resulting enhanced calcium uptake gets deposited into bone rather than soft tissue, which is an especially important benefit for those with osteoporosis.

[ Natural Sources ]

Vitamin K1 is typically found in green vegetables such as broccoli, leeks, Brussels sprouts, spinach, turnip greens, collards, lettuce, and asparagus. Vitamin K2 can be found in a few dairy products as well as some fermented food. It can also be produced from bacteria within the human colon.

[ Warnings ]

The American Cancer Society warns against the use of foods containing K2 for people taking blood thinners, as K2 is absorbed slower and lingers longer in the human body. While there is no established upper limit on vitamin K consumption, those on blood-thinners should discuss supplementation with their doctors before taking it.

[ Recommended Dosage ]

Males and Females, 0-6 months                          2 mcg

Males and Females, 7-12 months                      2.5 mcg

Males and Females, 1-3 years                            30 mcg

Males and Females, 4-8 years                            55 mcg

Males and Females, 9-13 years                          60 mcg

Males and Females, 14-18 years                       75 mcg

Males, 19 or older                                                 120 mcg

Females, 19 or older                                              90 mcg

Pregnant or lactating females 18 or older          75 mcg

Pregnant or lactating females 19 or older          90 mcg

[ Vitamin K Picks ]

Source Naturals Vitamin K, $7, 100 tablets, // Country Life Vitamin K-1, $8, 100 tablets, // Solgar Vitamin K2 Mk-7, $19, 50 veggie caps, // KAL Balanced K2, $11, 60 tablets,