Vitamin K – King of the Unsung Nutrient Heroes?
From blood to bones to heart, this rarely talked about vitamin may have a range of potential health benefits.
Vitamin K Basics
Vitamin K is a fat-soluble vitamin, stored in the body's fat tissue and liver. It can be obtained through the diet, mainly from plant sources such as leafy greens (kale, chard), brassica vegetables (broccoli, Brussels sprouts, cabbage) and soybeans, as well as from dairy sources such as milk, cheese and yogurt. Vitamin K is also produced by bacteria living in the intestine.
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Vitamin K is very sensitive to heat, excessive cold and light, so overcooking, freezing and storage can easily destroy the nutrient in foods. Destruction of gut bacteria, such as through frequent use of antibiotics or due to digestive disorders, can also deplete vitamin K in the body.
Daily vitamin K requirements are 90 mcg for women 19 and over and 120 mcg for men 19 and over. The three main types of VK are K-1, which is derived from plants; K-2, menaquinone, which is produced by the intestinal flora; and K-3, which is a synthetic, water-soluble form.
Deficiency is most common in those with conditions that impair fat or vitamin K absorption, such as liver and pancreatic diseases, celiac and Crohns disease, gastric bypass surgery, and cystic fibrosis, as well as in those who take warfarin, the weight loss medication Orlistat (Alli), or use antibiotics long-term. Infants are also at risk, which is why they receive a vitamin K shot shortly after birth.
Vitamin K Benefits
The most studied functions of vitamin K have been its role in blood clotting and bone building, with new research further supporting this, and also raising the possibility of benefits for artery and heart health.
Blood Clotting
Blood clotting, or thickening of the blood, is necessary to prevent uncontrolled bleeding after a cut or injury. To do this, the body uses a series of blood-clotting proteins, some of which must be activated by Vitamin K, which makes the nutrient critical to the clotting process. Without it, excessive bruising or hemorrhaging could occur. (1)
If you are taking prescription blood thinners such as warfarin or coumadin, talk to your doctor before taking Vitamin K supplements as it may interfere with the effectiveness of the medications.
Bone Health
Vitamin K is needed for proper use of calcium in bones; it activates osteocalcin, a protein found in bones that attracts and holds calcium in bone tissue. Without vitamin K, calcium is not able to build healthy bones.
Higher vitamin K levels correspond to greater bone density, while low levels of vitamin K have been found in those with osteoporosis. There is increasing evidence that vitamin K improves bone health and reduces risk of bone fractures, particularly in postmenopausal women who are at risk for osteoporosis. In addition, studies of other groups (such as male and female athletes) have also shown bone enhancing benefits from vitamin K supplements. (2, 3)
Heart and Vascular Health
Researchers believe that while vitamin K helps bind calcium to bones, it may also help keep calcium deposits out of the arteries. The potential for vitamin K to decrease calcification of the arteries is one way it could help reduce the risk of cardiovascular disease.
In one study, vitamin K supplementation was associated with a slowed rate of calcification of the coronary arteries that feed blood to the heart in men and women who already had calcification in those areas. (4)
Another study reported that increased intakes of vitamin K2 (but not vitamin K1) may decrease the risk of coronary heart disease in postmenopausal women. The long-term study found that for every 10 microgram increase in the amount of vitamin K2 consumed, there was a 9 per cent reduction in the risk of developing coronary heart disease. (5)
No Longer Unsung
Because of its long-known association with bone health, vitamin K has always been an important part of our Bone Support formula. And with the new research on the other potential benefits, vitamin K-2 was added to the new Basic Nutrient Support this past year.
Sources:
1. http://lpi.oregonstate.edu/infocenter/vitamins/vitaminK/
2. University of Maryland Medical Center, Complementary Medicine Guide
3. http://www.nutraingredients.com/Research/Review-supports-vitamin-K-s-fra...
4. Am J Clin Nutr. 2009 Jun;89(6):1799-807. "Vitamin K supplementation and progression of coronary artery calcium in older men and women"
5. Nutrition, Metabolism and Cardiovascular Diseases, 28 January 2009. "A high menaquinone reduces the incidence of coronary heart disease in women"
