Vitamin K, also known as the blood-clotting vitamin is a group of fat-soluble vitamins that play a vital role in blood clotting and preserving bone health. The K in vitamin K comes from the German word koagulation meaning clotting of the blood.
Vitamin K is required by the body to produce prothrombin, a protein produced by the liver that helps in proper clotting of the blood.
Types Of Vitamin K 
- Vitamin K1 (phylloquinone) - It is produced by plants found in foods such as kale, spinach, broccoli, collard greens, turnip greens, Brussels sprouts, red or green grapes, plums, kidney beans, etc.
- Vitamin K2 (menaquinones) - It is found in animal and fermented foods like natto, pork sausage, hard and soft cheese, pork chop, chicken, egg yolk, and so on.
Health Benefits Of Vitamin K
1. Supports bone health
Low levels of vitamin K have been linked to osteoporosis. Studies have shown that vitamin K helps maintain strong bones and decreases the risk of fractures. As per a study, vitamin K was given to 440 post-menopausal women with osteopenia for 2 years and the results were a 50% reduction in bone fractures . In addition, vitamin K lowers age-related osteoporotic fractures and maintains lumbar bone mineral density.
2. Prevents heart disease
Vitamin K inhibits vascular calcifications, they are mineral deposits that accumulate on the walls of the arteries and veins. Sometimes, these mineral deposits stick to plaques that are already built upon the walls of the blood vessels and this can increase the risk of heart disease and stroke .
3. Improves cognitive health
Vitamin K plays a key role in the proper functioning of the central nervous system. Studies have shown that the intake of vitamin K may improve cognitive function in healthy older adults. Vitamin K1 was linked with better verbal episodic memory performances, especially in recalling memories .
4. Lowers blood sugar levels
Another health benefit of vitamin K is it can significantly improve insulin sensitivity and increase glucose tolerance. According to a study published in the Journal of Nutrition and Metabolism, increased intake of vitamin K1 was shown to reduce the risk of developing diabetes by 51% .
5. May prevent tumour growth
Vitamin K has been shown to suppress the growth of cancer cells and prevent the occurrence of tumour growth. In a study, 11,319 men who had a higher intake of vitamin K2 was associated with a significant reduction in advanced stage of prostate cancer .
6. Prevents osteoarthritis
Vitamin K deficiency has been linked to abnormal mineralization of cartilage and bone. Inadequate intake of vitamin K has been shown to increase the risk of knee osteoarthritis and lesions in the cartilage .
7. Enhances skin health
Vitamin K helps in clotting of the blood, which aids in healing wounds, bruises and post-operative surgery wounds. This vitamin also treats certain skin conditions like scars, dark spots, stretch marks and dark circles under your eyes.
Sources Of Vitamin K
- Soybean oil
- Coleslaw with home-made dressing
- Red or green grapes
- Kidney beans
- Egg yolk
- Soft cheese
- Hard cheese
- Chicken liver
- Chicken breast
- Ground beef
- Fermented milk (kefir)
Can too much vitamin K be harmful?
People with kidney and liver disease who have excess amounts of vitamin K can make clotting problems worse for them. In addition, vitamin K can interact with certain medications like blood-thinners, anticonvulsants, cholesterol-lowering medicines and antibiotics.
Is it safe to take vitamin K daily?
According to the National Institutes of Health, the daily intake of vitamin K depends on age and gender. The daily recommended amounts are listed below:
- Birth to 6 months - 2.0 mcg
- 7 to 12 months - 2.5 mcg
- 1 to 3 years - 30 mcg
- 4 to 8 years - 55 mcg
- 9 to 13 years - 60 mcg
- 14 to 18 years - 75 mcg
- Men aged above 19 years - 120 mcg
- Women aged above 19 years - 90 mcg
- Pregnant or breastfeeding teens - 75 mcg
- Pregnant or breastfeeding women - 90 mcg
What happens if you don't get enough vitamin K?
Deficiency in vitamin K leads to bruising and bleeding problems because the blood takes a longer time to clot and it will also decrease bone strength and increase the risk of osteoporosis.
What are the symptoms of low vitamin K?
The symptoms of vitamin K deficiency are bruising easily, blood in the urine or stool, blood coming out from gums and nose, heavy menstrual periods, excessive bleeding from wounds, and so on.