Vitamin K (phylloquinone)

Introduction to Vitamin K

Vitamin K is a fat-soluble vitamin that plays a crucial role in blood clotting and bone health. It was first discovered in 1929 by Danish scientist Henrik Dam, who found that chickens fed a diet lacking in this vitamin developed bleeding disorders. The name “K” comes from the German word “koagulation,” which means blood clotting. There are two main forms of vitamin K: phylloquinone (K1) and menaquinone (K2). In this article, we will focus on phylloquinone, the primary dietary source of vitamin K.

Functions of Vitamin K in the Body

Vitamin K is essential for the production of several proteins involved in blood clotting, including prothrombin, which is converted to thrombin during the clotting process. Without vitamin K, bleeding disorders such as hemophilia can occur. In addition to its role in blood clotting, vitamin K is also important for bone health. It helps to activate osteocalcin, a protein that binds calcium to bones and teeth. Studies have shown that low levels of vitamin K are associated with an increased risk of osteoporosis and fractures.

Sources of Vitamin K

Phylloquinone is found in green leafy vegetables such as spinach, kale, and broccoli, as well as in vegetable oils such as soybean and canola oil. It is also present in smaller amounts in other foods such as meat, dairy products, and eggs. The bacteria in our gut can also produce some vitamin K, although this is not enough to meet our daily needs.

Food	Vitamin K (mcg)	% Daily Value
Kale, cooked (1 cup)	1062.0	885%
Spinach, cooked (1 cup)	888.5	740%
Collard greens, cooked (1 cup)	836.0	697%
Swiss chard, cooked (1 cup)	573.0	478%
Mustard greens, cooked (1 cup)	419.0	349%
Broccoli, cooked (1 cup)	220.0	183%
Brussels sprouts, cooked (1 cup)	219.0	183%
Cabbage, cooked (1 cup)	82.0	68%
Green beans, cooked (1 cup)	14.4	12%
Carrots, cooked (1 cup)	16.9	14%
Blueberries (1 cup)	28.6	24%
Grapes (1 cup)	22.5	19%
Prunes (5 prunes)	27.0	23%
Soybeans, cooked (1 cup)	47.8	40%
Beef liver, cooked (3 oz)	36.0	30%

Note: Percentages are based on the recommended daily value of vitamin K for adults, which is 120 mcg. Please note that percentages may vary depending on age, gender, and other factors.

Recommended Daily Intake of Vitamin K

The recommended daily intake of vitamin K varies depending on age and gender. For adults, the recommended daily intake is 90 micrograms for women and 120 micrograms for men. Pregnant and breastfeeding women may need higher amounts. It is important to note that vitamin K is a fat-soluble vitamin, which means that it is stored in the body and can accumulate over time. Therefore, it is important not to exceed the recommended daily intake to avoid toxicity.

Deficiency and Toxicity of Vitamin K

Vitamin K deficiency is rare in healthy adults, but it can occur in infants who are not given a vitamin K injection at birth, people with malabsorption disorders, and those taking certain medications such as antibiotics or blood thinners. Symptoms of vitamin K deficiency include easy bruising, bleeding gums, and nosebleeds. Severe deficiency can lead to hemorrhaging and even death. On the other hand, vitamin K toxicity is also rare but can occur with high doses of supplements. Symptoms of toxicity include nausea, vomiting, and jaundice.

Interesting facts about Vitamin K:

1. Vitamin K is a fat-soluble vitamin that is essential for blood clotting and bone health.
2. Vitamin K is found in many foods, including leafy green vegetables, such as kale, spinach, and broccoli, as well as in some fruits, meats, and dairy products.
3. Vitamin K deficiency can lead to bleeding disorders, such as easy bruising and bleeding gums, as well as an increased risk of bone fractures.
4. Vitamin K is also being studied for its potential role in reducing the risk of certain types of cancer, such as liver and prostate cancer.
5. Vitamin K is available in two forms: Vitamin K1, which is found in plant foods, and Vitamin K2, which is produced by bacteria in the gut and found in animal products.
6. Vitamin K is important for maintaining healthy bones, as it helps to activate proteins that are involved in bone mineralization.
7. Vitamin K is also important for maintaining healthy blood vessels, as it helps to prevent the buildup of calcium in the arteries.
8. Vitamin K supplements are available, but it is generally recommended to obtain Vitamin K from food sources rather than supplements.
9. The recommended daily intake of Vitamin K for adults is 120 mcg, although higher doses may be recommended for certain individuals, such as those taking blood-thinning medications.
10. Vitamin K is sensitive to heat and light, so it is best to store foods containing Vitamin K in a cool, dark place to preserve their nutrient content.

Conclusion: Importance of Vitamin K in Health

Vitamin K is an essential nutrient that plays a critical role in blood clotting and bone health. It is found in a variety of foods, with green leafy vegetables being the best source. The recommended daily intake varies depending on age and gender, and it is important not to exceed this amount to avoid toxicity. While vitamin K deficiency is rare in healthy adults, it can occur in certain populations and can lead to serious health consequences. Therefore, it is important to ensure adequate intake of this important nutrient for optimal health.

In conclusion, vitamin K is a vital nutrient that should not be overlooked in a healthy diet. By including a variety of vitamin K-rich foods in your diet, you can help support healthy blood clotting and bone health. If you are concerned about your vitamin K intake, talk to your healthcare provider or a registered dietitian for personalized recommendations.