Do you know why vitamin K is known by letter K? K comes from the word “koagulate” in German which mean clotting that because vitamin K has a significant role in blood clotting. Vitamin K is a particular vitamin as it is one of the few that can be produced inside the body through the metabolism of bacteria in the large intestines. It is also the only fat-soluble vitamin that not stored inside the body. Vitamin K has two categories including vitamin K1 and vitamin K2, and our bodies need both of them for blood clotting, the normal function of the cardiovascular system, as well as bone and teeth health. Deficiency of vitamin K incidence is low, but it mostly affects newborns as they cannot produce it before 6 months. Thus, newborns are at risk of developing a condition called vitamin K deficiency bleeding (VKDB). Vitamin K deficiency causes consistent bleeding as it affects the body clotting mechanism.
Why vitamin K and what’s its benefits?
There are general benefits of vitamin K, such as:
○ Decrease cancer incidence
○ Supports the immune system
Also, vitamin K has other benefits related to its types such as:
Vitamin K1, also known as phylloquinone, helps with:
○ Maintaining blood hemostasis
Vitamin K plays a significant role in blood clotting, as it is important to produce prothrombin, which is the main component for the clotting system.
Vitamin K2, also known as menaquinone, helps with:
○ Supports bone health and teeth
Vitamin K2 has a significant role in calcium deposition in the bone, prevents bone breakdown and calcium deposition in other tissues like the kidney, which in turn decreases the formation of kidney stones. In teeth, it helps with calcium deposition and prevents teeth decay.
○ Sustains healthy blood vessels
It helps with blood vessel elasticity and integrity as it restores blood vessels after tear or injury to their normal condition. It also prevents calcification as a part of its action on calcium.
Where can I get vitamin K from?
– Vitamin K is an umbrella term consisting of two categories: phylloquinone, vitamin K1 and menaquinone, vitamin K2. The two categories have different sources, absorption, mechanisms of action and benefits. The majority of vitamin K2 in the body is produced by intestinal flora, the good bacteria in the large intestine, by converting vitamin K1 to K2. Intestinal or gut floral also convert vitamin K2 to its other forms like vitamin K2-MK7 and MK11.
– Phylloquinone or Vitamin K1 is found in plants products especially leafy greens like kale, spinach, broccoli, Brussels sprout, okra, lettuce, mustard greens, swiss chard, kelp, spring onions, turnip greens, cabbage, basil, asparagus. Leafy greens have a high amount of vitamin K because they help with the photosynthesis in plants.
– Menaquinone or vitamin K2 is found in an animal product like chicken and eggs, in fermented food like natto or fermented soybean and pickled cucumber and dairy products like hard cheese such as gouda and swiss, Jarlsberg and blue cheese.
Here are some of the highest vitamin K sources and the amount of vitamin K in 100 grams of each source:
- Kale: 1062 μg, 885% of daily vitamin K intake
- Natto, fermented soybean: 1000 μg, 833% of daily vitamin K intake
- Goose liver: 369 μg, 307% of daily vitamin K intake
- Broccoli: 220 μg, 183% of daily vitamin K intake
- Brussels sprouts: 219 μg, 182% of daily vitamin K intake
- Cabbage: 163 μg, 163% of daily vitamin K intake
- Pickled cucumber: 130 μg, 109% of daily vitamin K intake
- Jarlsberg cheese: 73 μg, 60% of daily vitamin K intake
- Asparagus: 91 μg, 76% of daily vitamin K intake
- Okra: 64 μg, 53% of daily vitamin K intake
How do our bodies absorb vitamin K?
The absorption of vitamin K differs according to its type.
♦ Vitamin K1, phylloquinone
- Less bioactive
- Converted by intestinal bacteria to vitamin K2
- Acts in the blood clotting system
- Found in plant sources
- Distributed to the liver then to the blood
♦ Vitamin K2, menaquinone
- More bioactive and better absorption
- Converted by intestinal bacteria to vitamin K2 forms K2-MK7 and K2-MK11
- Support bone and teeth
- Restricted to animal products and fermented food
- Easily distributed in bones and other tissues
People usually ingest vitamin K1 10 times more than K2
Here are some factors that may enhance or reduce vitamin K absorption:
Increase healthy fats with vitamin K rich food like avocados, olive oil, butter, nuts and seeds. Fats increase vitamin K absorption because it is a fat-soluble vitamin.
Add foods high in probiotics to your diet like yoghurt, kefir and sauerkraut. Probiotic is the favourite meal for good bacteria in the gut and increases their multiplication.
- Coffee and tea
They should be avoided as they decrease vitamin K absorption.
It acts as a diuretic and will cause a loss of vitamin K in urine. It also damages digestive system lining, which results in vitamin K malabsorption.
How much vitamin K do I need daily?
Daily recommendations of vitamin K differ according to age, sex, daily activity, the person’s status of health, metabolic and medical conditions. However, the recommended vitamin K amount, according to the World Health Organization (WHO), is as follows:
- From birth to 6 months: 2 μg
- Infants from 7 to 12 months: 2.5 μg
- Children from 1 to 3 years: 30 μg
- Children from 4 to 8 years: 55 μg
- Children from 9 to 13 years: 60 μg
- Teens from 14 to 18 years: 75 μg
- Male adults from 19 years and older: 120 μg
- Female adults from 19 and older: 90 μg
- Pregnant and breastfeeding teens from 14 to 18: 75 μg
- Pregnant and breastfeeding women from 19 and older: 90 μg
*microgram (μg, mcg)
People at risk of vitamin K deficiency may need more than the daily vitamin K recommendation.
Who is at risk and what are the causes of vitamin K deficiency?
• Low vitamin K intake
Low vitamin K diet and Plant-based diet because vitamin K is hard to absorb from plant sources and need to convert first to its active form while animal products are absorbed more efficiently and have a higher bioavailability.
Pregnancy and breastfeeding women are at risk because the nutritional demand of the infant increases vitamin K requirements, and may cause vitamin K deficiency when this is not prevented with supplements or by increasing vitamin K intake in food.
• Malabsorption and digestive system diseases
Patients with an intestinal disease that decreases vitamin K absorption such as celiac and Crohn’s diseases should consider vitamin K supplements and these conditions must be treated to avoid its deficiency.
In chronic alcohol consumption, there is an increase in vitamin K excretion in urine.
• Infants and newborns
Newborns are the largest group that is highly susceptible to vitamin K deficiency around the globe. Mothers of a newborn don’t provide a sufficient amount of vitamin K to her child during pregnancy nor breastfeeding stages because vitamin K doesn’t pass easily through the placenta or in milk. Additionally, a newborn’s intestine is devoid from healthy bacteria that convert and produce vitamin K which make them predisposed to vitamin K deficiency. Vitamin K injection is a mandatory measure for all infants after birth.
• Gall bladder diseases
Diseases that decrease bile secretion may lead to a deficit in vitamin K absorption because bile helps with fat absorption and without fat vitamin K will not absorb because it is a fat-soluble vitamin.
When do you consider vitamin K deficiency?
Normal vitamin K levels range between 0.2 to 3.2 nanogram per milliliter (ng/ml). If the test is lower than 0.2 ng/ml means vitamin K deficiency, but bleeding disorders appear when vitamin K levels at 0.5 ng/ml or below. A blood test is rarely recommended, and it is not used for measuring vitamin K. When bleeding occurs, and vitamin K deficiency is suspected, the first option will be performing a prothrombin time (PT) test.
How do you know that you have vitamin K deficiency and when you need to seek professional advice?
○ Bleeding disorders
Such as bleeding gums, unexplained bruises, blood in urine and stool and heavy periods. This happens because vitamin K is responsible for blood clotting and with its deficiency, bleeding will occur consistently and quickly.
Vitamin K deficiency causes increased calcium deposition outside the bone, which causes calcification and hardening of the blood vessels, giving rise to hypertension.
○ Joint Pain
This is because of excessive calcium deposition in the joint which causes pain during movements of joint.
How to maintain vitamin K at a healthy level and prevent vitamin K deficiency?
– Eat food rich in vitamin K like leafy green vegetables including spinach, broccoli, basil, chives, dill, okra, chard and lettuce.
– Treat medical conditions that affect vitamin K metabolism and liver diseases that decrease bile formation and secretion.
– Use vitamin K supplements, preferably injection, especially with people how are at risk of vitamin K deficiency as pregnant and breastfeeding women.
– Talk to your doctor if you have a family history of osteoporosis.
– Avoid calcium, zinc-rich food for 2 hours before or after vitamin K rich meals.
– Avoid alcohol consumption.
– Newborn vitamin K injection is mandatory to prevent vitamin K deficiency bleeding (VKDB). Every newborn must be injected with vitamin K as a protective measure.
– Include more healthy fat sources in each meal to increase vitamin K absorption in the intestine. You will find healthy fat in various oils, avocados, nuts and seeds including almonds, peanuts, cashews, brazil nuts, pine nuts, sesame seeds, flax seeds, watermelon seeds, pumpkin seeds and sunflower seeds.
– Vitamin K3 supplement pills should be avoided as they are associated with signs of toxicity.
How can you treat a vitamin K deficiency?
– You should elevate vitamin K levels in the blood by working on the same points as in the prevention of vitamin K deficiency. You can ask your doctor, as he may recommend vitamin K supplements to increase its levels. Vitamin K supplements are available over the counter, and for most adults, the recommended daily allowance is 120 μg for adult males and 90 μg for adult females.
– Always ask your doctor before taking supplements, even if it is available over the counter. Vitamin K supplements can cause thrombosis because of its clotting properties and should be monitored closely.
– Vitamin K supplements interfere with certain medications such as warfarin.