Green-leafy vegetables are a natural and rich source of vitamin k which, according to scientists, play a critical role in bone metabolism and the prevention of osteoporosis. Unfortunately, doctors who treat patients with osteoporosis pay little attention to vitamin k deficiency.
The forgotten- and for some the unknown- vitamin K
Vitamin K is a group of fat-soluble vitamins that play very important role in blood clotting, a critical body function which stops bleeding after an injury. The last decade, scientists studied further the role of vitamin k and after extended research they concluded that its role goes beyond the blood clotting, since vitamin k found to be associated with the maintance of calcium in the bones. There are two main types of vitamin k: the K1 (phylloquinone) commonly found in leafy vegetables and, K2 (menaquinone) found in dairy or meat products.
How the vitamin k builds strong bones
Vitamin k was found to play important role in bone metabolism as it affects the calcium balance. It does so by increasing the amount of osteocalcin, a key protein involved in bone mineralization and upon which calcium crystallizes. Without osteocalcin our bone mineral density diminishes significant and our skeleton is very fragile. In other words, the synthesis of osteocalcin is vitamin k depended and is strongly associated with the bone mineral density. The higher levels of osteocalcin the stronger bones we have but once the levels of this protein drop we come close to osteopenia and the onset of osteoporosis.
Epidemiological studies and clinical trials consistently indicate that vitamin k has a positive effect on bone mineral density and decreases fracture risk. Source: NCBI
The best way to describe how vitamin k works is to imagine it as the ‘glue’ that binds the calcium onto our bones. This comes to challenge the previous theory according to which calcium was the No 1 component for strong bones. What’s more, now scientists can prove that the building of a strong skeleton is a combination of Vitamin D, Vitamin K and Calcium and not calcium alone. Vitamins D and K work synergastically on bone density. So, no matter how much calcium you take through your diet (consuming milk, cheese, yogurt, etc) if you have a deficiency in both Vitamin D and K, your bones simply cannot maintain the calcium. Another important fact is that, the Institute of Medicine increased the previous dietary reference intake of vitamin k up to 50%, suggesting that women take 90mg/day and men 120 mg/day.
Deficiency and Overdose of vitamin K
It is worth it to mention that Vitamin K is also produced in the body by some beneficial intenstinal bacteria but the problem is that the poor quality food, the excessive fats and sugar, the excessive use of antibiotics, some liver diseases and the gastrointestinal problems can easily lower the levels of Vitamin K. However, a well-balanced and nutrient-based diet rarely leads to vitamin k deficiency. In case you have a deficiency of this vitamin though, the first sign that should alert you is the difficulty to stop bleeding after an injury but it’s not the only one. You may notice a constant gum bleeding or your nose bleeds suddenly. Body bruises and easily fractured bones, tooth decay or the loss of teeth are also signs of vitamin k deficiency. On the other hand, a vitamin k overdose can lead to hypervitaminosis and cause an allergic reaction and liver toxicity. When i say overdose i mean an intake over 500mg/day, that is quite a lot and impossible to take so much through diet. Remember that every vitamin in such a dosage can be toxic for the liver so as we say in Greece ”παν μέτρον άριστον” that is ”all in good measure”.
Natural Sources of Vitamin K
- spring onions
- brussel sprouts
Any green-leafy vegetable is an excellent natural source of vitamin k, since it is the chlorophyll, which gives vegetables the green color, that contains the vitamin k . Once you add green salads in your diet you are 100% covered in vitamin k and there is no need for supplement.
Other Benefits of vitamin k
No vitamin has only one role to play in our body function. This is why scientists constanly make researches once there is always something new to be found. Among other benefits of vitamin k are:
- fights cancer
- promote heart healt
- improve insuline sensitivity
- boost brain function
So, now that you know how important Vitamin K is for your health, what else are you waiting for to go…green?!
source: National Institute of Health