|In a nutshell|
|Vitamin K is necessary for normal blood clotting and bone health.|
|Antibiotics taking can be one of the reasons for the vitamin deficiency – it harms good intestinal microbiota which is an important Vitamin K (K2) supplier.|
|There are no toxicity or overdose concerns for the intake of the natural or
supplement forms of this vitamin.
Vitamin K deficiency
Vitamin K deficiency. Although a deficiency of this vitamin is rare, it can be caused by certain factors. K deficiency usually develops as a consequence of malabsorption, and not as a result of its lack in food. People who take antibiotics for long time periods (antibiotics harm good intestinal microbiota), people with certain health conditions and diseases, or people who suffer from serious burns may all be under increased deficiency risk.
Symptoms of a deficiency in this vitamin include:
• Excessive bruising or bleeding;
• Loss of bone or decrease in bone density;
• Calcium deposits, especially in soft tissue.
Vitamin K overdose
Vitamin K overdose. There are no toxicity or overdose concerns for the intake of the natural or supplement forms of this vitamin found in the United States. Therefore, there is no maximum limit for this vitamin set. Studies have been done on people who eat high levels of this vitamin naturally through diet and who also take supplements with no adverse effects to be found. There is one man-made version of this vitamin, known as menadione or K3, that can cause damage to cells, especially in the liver or kidneys. Menadione is prohibited to be sold as a supplement in the United States.
Daily Recommended Intake and sources of vitamin K
Daily Recommended Intake. Daily recommended intake of the vitamin for adults is 90-120 µg.
The following foods have high amounts of K2:
• Goose liver – 100 g contain 369 µg;
• Hard cheeses – 100 g contain 76 µg;
• Soft cheeses – 100 g contain 57 µg;
• Chicken liver – 100 g contain 13 µg;
• Plant sources of K1 like kale, spinach, greens, swiss chard, parsley, brussel sprouts, romaine lettuce, and broccoli contain 220-530 µg of the vitamin in half cup of the cooked product.
Enough of this vitamin can be obtained from eating just one of these foods on a daily basis.
Other important sources of the vitamin:
• Chicken breast;
• Whole milk;
Why “K”? This vitamin was identified in 1935 by a Danish scientist who was studying clotting of blood. Henrik Dam named this as Koagulations-vitamin, using the German word for blood clotting. This mouthful was later shortened and the vitamin was named “K”.