Vitamin K is a precious ally for human health, a fat-soluble substance released by the body only when needed. This vitamin, accumulated in the liver, plays a vital role in blood clotting and maintaining bone health. It is important to note that vitamin K is fat-soluble, meaning it is only effectively absorbed when ingested with lipids. This vitamin performs essential functions in our body, and its deficiency can have serious consequences, especially in newborns. Vitamin K is present in different forms.
In this article we will explore the role of vitamin K, the food sources in which it is present, when supplementation is necessary and possible contraindications.
The Role of Vitamin K
Vitamin K plays a fundamental role in blood clotting, ensuring that our body can heal from wounds without incurring bleeding. Furthermore, it contributes to bone health, often associated with the intake of vitamin D. In some cases, you can find supplements containing both of these vitamins. It is clear how dangerous a deficiency of this vitamin is for human health, which can occur due to diseases that limit its intestinal absorption or due to prolonged use of antibiotics.
Vitamin K also plays a key role in cardiovascular health, reducing the risk of atherosclerosis, a condition in which artery walls harden due to the buildup of calcium, cholesterol, inflammatory cells and fibrotic material. Recent studies have also suggested a link between vitamin K intake and a lower incidence of brain cell inflammation, reducing the risk of cognitive decline, similar to what is observed with some B vitamins, such as B6 and B12, which counteract this form of cognitive deficit.
Different Forms of Vitamin K
There are three main forms of vitamin K:
- Vitamin K1 (Phylloquinone): This form is obtained through nutrition and is abundant in green leafy vegetables such as kale, spinach and lettuce. Vitamin K1 supports the blood clotting process.
- Vitamin K2 (Menaquinone): This form is produced in our body, mainly by intestinal bacteria, and is present in some fermented foods. Vitamin K2 is critical for bone health and can help prevent osteoporosis.
- Vitamin K3 (Water-soluble Menadione): This form is chemically synthesized and is used in the medical field for the formulation of drugs that regulate blood clotting.
Food Sources of Vitamin K
You can get both vitamin K1 and K2 by following a balanced diet. Here are some of the main food sources:
- Green Leafy Vegetables: Such as cabbage, spinach, broccoli and green cabbage, also rich in folic acid (vitamin B9).
- Vegetable oils: Such as soybean oil and canola oil.
- Fruit: Like blueberries, strawberries, kiwis and figs.
- Natto: A Japanese food derived from the fermentation of soybeans, particularly rich in vitamin K. It is also considered useful in reducing LDL cholesterol and the risk of cardiovascular disease.
- Fermented Products: Such as cheeses and whole yogurt, which contain fair quantities of this vitamin.
The daily requirement of vitamin K in adults is approximately 140 micrograms per day. This quantity can easily be achieved with a varied and balanced diet, including at least 200 grams of vegetables per day and integrating foods such as yogurt and cheese.
Vitamin K deficiency
Vitamin K deficiency in healthy adults is rare, but can occur in some conditions, such as chronic diseases that reduce intestinal absorption, prolonged antibiotic treatment, or anticoagulant therapy. In the latter case, taking drugs such as warfarin can reduce blood clotting and affect the function of vitamin K.
Vitamin K Deficiency in Newborns
In newborns, vitamin K deficiency is more common and can cause serious problems. During the first few months of life, breastfed babies may be at risk of vitamin K deficiency unless they are given a vitamin K supplement shortly after birth. Vitamin K deficiency in newborns can lead to potentially fatal bleeding, known as “vitamin K deficiency hemorrhages.”
Contraindications and Side Effects
Before taking vitamin K supplements, it is important to consult a doctor. Excessive intake of vitamin K can lead to side effects such as reduced liver function, hot flashes and tightness in the chest. Supplements, even if natural, should only be taken if there is a real need and under the supervision of a health professional.
In conclusion, vitamin K is crucial for our general well-being, but it is essential to maintain an adequate supply through a balanced diet. If you have any doubts about the need for supplements, it is always best to consult a doctor for a precise evaluation.