Vitamin K is an antioxidant that neutralizes free radicals that damage cell membranes, needed to form cartilage, bone and dentine, decreases calcium loss and helps maintain bone mass, helps prevent and treat osteoporosis. Sources include cooked leafy greens, cabbage, broccoli, brussel sprouts, soybeans, vegetables, asparagus, beet greens, broccoli, and green cabbage.
Quick Facts
-A group of similar molecules, the two forms that occur in nature being K1 and K2.
-K1 is made by plants
-K2 is made from K1 by bacteria. K2 includes a range of different forms, specifically, MK-4, and K7 – K11 are important.
-Required to complete synthesis of proteins needed for blood clotting, without which uncontrolled bleeding occurs. These proteins are also required for binding of calcium in bones and other tissues
-Not water soluble [60]
-Antioxidant that neutralizes free radicals that damage cell membranes, needed to form cartilage, bone and dentine, decreases calcium loss and helps maintain bone mass, helps prevent and treat osteoporosis [160]
RDI
Males 19 – 30 yrs: 120 μg
Females 19 – 30 yrs: 90 μg
[128]
Deficiency
-Easily bruised, slower blood clotting so more bleeding – including from the nose stomach or intestines, which may cause blood to be vomited or appear in stool, osteoporosis/low bone density, easily fractured bones [160]
Toxicity
-Extremely rare. Non-toxic even when consumed in high quantities so no upper limit
-Some forms of supplements may be toxic, but the natural forms K1 and K2 are non-toxic
-Too much may lower blood sugar levels [178]
Sources
Cooked leafy greens, cabbage, broccoli, brussel sprouts [60], soybeans, vegetables, asparagus, beet greens, broccoli, green cabbage, cauliflower, swiss chard, collard greens, garden cress, kale, lettuce, mustard greens, romaine lettuce, spinach, turnip greens, watercress [160]
*Bioavailability increases when consumed with fats
