Today I want to tell you about a vitamin that is given too little attention – vitamin K.
Vitamin K, also known as phylloquinone or menaquinone, is essential for proper blood clotting. In addition, it plays an important role in bone formation. Recently, there have been interesting scientific studies that demonstrate the importance of this vitamin for heart health.
Vitamin K is fat-soluble. This means that it is best absorbed in the presence of dietary fat. There are two forms of vitamin K – K1 and K2. K1 or phylloquinone is naturally found in foods, mostly in green vegetables and herbs. Colon bacteria produce a certain amount of menaquinone, or vitamin K2. Small amounts of vitamin K 2 are present in eggs and dairy products. We get about 90% of vitamin K from food, about 10% is produced by our intestinal bacteria.
Vitamin K is vital for babies
In the Netherlands, where I live, all babies receive vitamin K immediately after birth. Babies who are breastfed are given 150 micrograms of vitamin K in drops for the first 12 weeks. The ready-made formulas (for babies who are not breast-fed) usually contain enough added vitamin K. However, if the amount of formula consumed is less than 500 ml per day, it is recommended to supplement extra vitamin K.
Why do babies need this vitamin? New-borns are deficient in vitamin K because they do not receive it during pregnancy from the mother. This is because vitamin K does not pass through the placenta to the foetus. Therefore, new-borns haven’t built up any reserve. In addition, the new-born baby has sterile intestines, that is, it does not yet have intestinal bacteria to produce vitamin K. It is therefore believed that new-borns are at risk of severe bleeding. That’s why they always get drops of vitamin K right after birth.
Vitamin K functions
Vitamin K is needed for blood clotting. If you are injured and are bleeding, it is important to stop the blood. This is only possible if it clots. If blood does not clot, it could completely leak out from one small wound!
Vitamin K is essential for optimal bone health. More specifically, vitamin K is required for the formation of osteocalcin, a substance that attracts calcium to the bone matrix.
Recently, studies have been conducted to study the effect of vitamin K on heart function. Scientists have found evidence that this vitamin may play a role in the prevention and treatment of arterial calcification and coronary heart disease. It should be noted that research on the effects of vitamin K on heart health is very recent and still limited, so there are no hard conclusions yet.
How much vitamin K do adults need?
Vitamin K and its health effects are less well studied than those of other vitamins. Therefore, not all countries have norms for the recommended dietary intake. An acceptable recommendation is 70 to 120 mcg per day.
Too little vitamin K
Antibiotics can kill intestinal bacteria that play a role in vitamin K production. Therefore, individuals who receive long-term antibiotics may become deficient in vitamin K. This can lead to slow blood clotting.
Too much vitamin K?
It is not known whether too much vitamin K is harmful. In practice, too much of this vitamin does not occur often. People taking blood thinners or anticoagulants should be careful with vitamin K supplements containing more than 100 micrograms of vitamin K. These can reduce the effect of the anticoagulants.
Food sources of vitamin K
In general, all edible green parts of plants can be considered important sources of vitamin K. Vitamin K is found in foods that are green: leafy greens, cabbages, herbs.
100 g spinach provide 480 mcg vitamin K (!).
Only 10 grams of parsley (10 sprigs) contain 165 mcg of vitamin K.
Broccoli is also an excellent source of this vitamin. It provides 100-160 mcg of vitamin K per 100 g.
Kale is also a great source of vitamin K. 100 g of kale provide 80 mcg of this vitamin.
During the heat treatment of food, the amount of vitamin K decreases slightly.