- What is vitamin K1?
- What is the role of vitamin K1?
- Why is vitamin K1 prescribed?
- Vitamin K1: what are its contraindications?
- What foods are rich in vitamin K1?
- Why give vitamin K1 to an infant?
- What are the recommended intakes and dosage of vitamin K1?
- What are the risks and signs of vitamin K1 deficiency?
- What side effects in case of overdose?
What is vitamin K1?
There are three forms of vitamin K.
There vitamin K1 (phylloquinone), of plant origin, is a fat-soluble vitamin that plays an important role in blood clotting. This “antihaemorrhagic” vitamin is also essential for the calcification or construction of bones. Indeed, it helps to fix calcium in the bones and to prevent osteoporosis. It is produced by bacteria in the gut flora and is found in plant foods (mainly leafy green vegetables), as well as in supplements and medications.
There vitamin K2 (menaquinone), of animal origin, is useful for soft tissues. It is also produced by the body, in part, and present in food. There is vitamin K3 (menadione), but it is a synthetic form (which becomes vitamin K2).
Finally, the vitamin k3 (menadione) is produced synthetically. However, this is no longer used in humans, as it has been linked to a risk of liver toxicity.
What is the role of vitamin K1?
Vitamin K1 has many health benefits. First of all, it is important for bone health. It promotes the action of a protein hormone that is part of the bone structure, osteocalcin. For the European Food Safety Authority, food supplements dosed at 11 µg (micrograms)/100 g of vitamin K contribute to the normal functioning of bones.
This vitamin also plays a key role in blood clotting, by activating proteins that help form blood clots. Furthermore, theVitamin K1 can help prevent calcium buildup in the arteries, which reduces the risk of cardiovascular disease.
Why is vitamin K1 prescribed?
Daily vitamin K1 requirements are normally provided by a varied and balanced diet. Supplementation is only indicated in case of proven deficiency or risk of deficiency. Taking vitamin K1 as a medicine therefore only concerns specific situations:
- newborns and some women before childbirth;
- people under treatment who can make bleeding (strong antibiotics, oral anticoagulants, drugs preventing normal absorption of vitamin K);
- intestinal diseases limiting the absorption of vitamin K;
- blood clotting problems;
- liver and gallbladder disorders.
Doctors administer vitamin K1 in the form of an injectable or drinkable solution (pipettes and ampoules).
Vitamin K1: what are its contraindications?
In the SPCs of injectables (Summary of Product Characteristics), the contraindications are above all allergies to the components of the drug (other than vitamin K). The intake of any anticoagulant should also be reported to the prescribing physician, as vitamin K1 may interfere with their effectiveness.
What foods are rich in vitamin K1?
THE foods rich in vitamin K1 are mostly dark green vegetables, such as spinach and the broccoli.
Vitamin K1 is also found naturally in cabbage :
- cauliflowers,
- Brussels sprouts,
- green cabbage,
- kale (kale).
But also in the asparagusgreen beans, chard or endives, not to mention the different varieties of lettuce.
Several plants are excellent sources of vitamin K1:
- parsley,
- watercress,
- fennel,
- thyme,
- the Basilic,
- turnip greens
- mustard leaves.
Some fruits also provide us with vitamin K1:
- the blueberries,
- The kiwi,
- the grenade
- apples.
Finally, vitamin K1 is present in soybeans and soybean oil.
If some foods should preferably be eaten raw to enjoy the benefits of vitamin K1, it is not sensitive to cooking. On the other hand, prefer fresh foods (if possible organic and seasonal) and keep them away from light.
Why give vitamin K1 to an infant?
Newborns should receive vitamin K1, in order to prevent bleeding. At birth, humans have almost no vitamin K1, because there are not enough intestinal bacteria to produce it.
Newborns who are not at risk receive a single intramuscular injection shortly after birth or an oral treatment in three doses: at birth, a few days later and then a month later. Premature and full-term babies who are at risk receive an injection at birth and further doses later, if needed. Full-term babies who are not at risk but who are exclusively breastfed also receive three doses of vitamin K1 by mouth. Breast milk is very low in vitamin K1.
These treatments are effective and safe.
What are the recommended intakes and dosage of vitamin K1?
THE recommended dietary allowances of vitamin K1 are not the same according to the health organizations. Today, for the National Agency for Food, Environmental and Occupational Health Safety (ANSES):
- adult men and women need 79 mcg of vitamin K1 per day. Requirements do not increase with pregnancy or lactation;
- the vitamin K1 needs of infants are 5 µg/day and 10 µg/day after six months of age;
- THE children and teenagers have requirements ranging from 29 µg/day to 45 µg/day.
In terms of dosage for vitamin K1 taken orally or injected, it depends on the drug. In infants, single doses are usually 1 or 2 mg and oral doses are 2 mg. They are much lower for premature newborns weighing less than 2.5 kg.
In adultsit is not recommended to exceed the dose of 25 µg per day (ANSES), with regard to vitamin K treatments, but the dosages may vary according to the patient.
What are the risks and signs of vitamin K1 deficiency?
While a lack of vitamin K1 in infants puts them at risk of bleeding, the risk of deficiency is non-existent in healthy adults. A varied diet covers our vitamin K1 needs.
People who lack vitamin K1 and need to take treatment usually suffer from diseases (intestinal, liver, etc.). The symptoms of a deficiency are above all too frequent bleeding (in particular nosebleeds) and a greater vulnerability to bruising.
What side effects in case of overdose?
Excess vitamin K1 from natural spring (i.e. through diet) does not cause any side effects. Even by consuming large amounts of foods rich in vitamin K every day, a healthy person does not assimilate all of it and the excess is eliminated by the body. On the other hand, people on anticoagulant treatment must watch their diet and vitamin K1 treatments are contraindicated with the taking of anticoagulants.
Although vitamin K1 supplementation (in drug form) is generally considered safe, it may cause side effects in some people. Common side effects include:
- stomach pain;
- nausea ;
- vomitings ;
- dizziness.
In rare cases, an overdose of vitamin K1 can lead to more serious complications, including excessive bleeding and liver problems. It is important not to exceed the recommended dose of vitamin K1 and to seek medical attention if you experience any adverse symptoms after taking a vitamin K1 supplement.
Validation: Doctor Anne-Christine Della Valle, general practitioner.
Source : Nutritional references for vitamins and mineralsHandles.
Read also:
- Vitamin B9 (folic acid): benefits, deficiency and overdose
- Vitamin D: what are the benefits? where to find it?
- 6 Telltale Symptoms of Vitamin B12 Deficiency
