Vitamin K comes into different forms: K-1 and K2. K1 is synthesized from plants which we eat and K2 is synthesized in animals, including humans, from bacteria in the intestines. K2 is found in higher concentrations than K1 in certain organs of the body, including the liver, which suggests that there is more to be discovered about the synthesis and use the vitamin K in the body. (1)
For the past several years researchers and doctors have believed that vitamin K has had a distinct role in the manufacture of bone and prevention of osteoporosis in postmenopausal women. Osteoporosis is a chronic bone condition that has a negative effect on the health of twice as many women as men over the age of 40. Bone loss occurs in everyone over the age of 35. Once a woman reaches menopause the preventative effects of estrogen are lost. Osteoporosis is a negative balance between bone growth and bone thinning.
Vitamin K has a role in building bone. It is a fat soluble vitamins that is essential for the functioning of several proteins important in blood clotting and also appears to be important in the ability to bind calcium to form bone. (1)
According to a study recently published an PLoS Medicine 440 postmenopausal women diagnosed with osteopenia (a warning condition of bone loss and precursor to osteoporosis) were studied. The women were given either vitamin K supplementation or a placebo for two years, and 261 continued for greater than two years.
The results found that bone density scans after two or four years had no differences between the two groups and that bone density had decreased by similar amounts across the board. However, the interesting discovery was that in the group of women who took the vitamin K supplementation fewer of those had fractures and fewer had developed cancer. (2)
One theory is that although some of the new medications will increase bone density they do not affect the micro-structure of the bone. This means that the new bone which is laid down as a result of taking drugs is actually weaker than bone laid down as a result of appropriate nutrition.
In the Nurses Health Study researchers followed more than 72,000 women for 10 years and found that women whose vitamin K intake was low had a 30% greater risk of hip fracture than those whose vitamin K intake was high. (3) In the Framingham Heart Study 800 men and women were followed over seven years and found that those who had vitamin K in the highest group had only 35% of the risk of fracture than those in the group who had the lowest intake of vitamin K. (4,5)
Food sources for vitamin K include olive oil, mayonnaise, broccoli, kale, spinach, leaf lettuce and parsley. In a study published in The American Journal of Health System Pharmacy researchers determined that vitamin K was effective in the prevention and treatment of osteoporosis and arterial calcification.
Although the majority of these studies have shown that vitamin K has a positive effect on the treatment of individuals who have osteoporosis and the prevention of low impact fractures, it is important to note that the same was thought in years past of calcium. This only points to the necessity of bringing together all of the vitamins and minerals necessary to build bone as opposed to dealing with a disease entity with the mistaken belief that one vitamin, one mineral or one drug is an effective overall treatment.
Instead, by bringing together medications for individuals who require assistance in developing bone density with appropriate additions of vitamin K, vitamin D, magnesium, calcium and weight-bearing exercises, prevention of osteoporotic low impact fractures can be thoroughly maximized.
http://health.net.au/health-living/ Vitamin K
(2) PLoS: Vitamin K Supplementation in Postmenopausal Women with Osteopenia: a Randomized Controlled Trial
(3) American Journal of Clinical Nutrition: Vitamin K Intake and Hip Fractures in Women: A Prospective Study
(4) American Journal of Clinical Nutrition: Dietary Vitamin K Intakes are Associated with Hip Fracture But Not with Bone Mineral Density in Elderly Men and Women
(5) American Journal of Clinical Nutrition: Vitmain K Intake and Bone Mineral Density in Women and Men