How vitamin K acts in healthy aging – 05/22/2023 – Equilibrium

That we do not bleed to death when we are injured or that tissues recover when damaged by an external agent are two of the basic functions of vitamin K.

Despite being less well known than vitamin C or D, it may hold the secret to healthy aging.

Vitamins are not boring

Now it may seem to us that studying vitamins is a boring thing, but a hundred years ago they were on the cutting edge of scientific wave. The name “vitamin” was proposed by the biochemist Casimir Funk in 1912. He used it to refer to essential substances in the diet, in small amounts, to maintain health.

From the isolation of thiamine (vitamin B1) in 1910 to folic acid in 1941, the study of these substances was a very active field in chemistry and physiology. The 1929, 1930, 1934, 1937, 1938 and 1943 Nobel Prizes were awarded for identifying and describing the functions of different vitamins.

Specifically, the history of vitamin K (Nobel Prize in 1943) is closely linked to coagulation. The name derives from the Danish “koagulation” and the previously proposed vitamin, being vitamin J (flavin), now renamed vitamin B2. It was discovered by detecting a substance in the diet with an anti-hemorrhagic effect, that is, it prevented bleeding.

Shortly afterwards, the presence of substances in cattle fodder was discovered that produced the opposite effect in cattle: the animals began to bleed spontaneously.

When these prohemorrhagic compounds were isolated, it was observed that their structure was similar to vitamin K. This led to their use in medicine as the first oral anticoagulants to prevent blood clots. They are what we call antivitamin K, such as acenocoumarol (the popular Sintrom®), which act in competition with vitamin K.

How does vitamin K work?

Although this vitamin’s effect on clotting has been known since the 1950’s and antivitamin K was used, it wasn’t until the 1970’s that we really began to understand how it works.

Vitamin K is needed to modify the structure of some amino acids that make up some proteins (less than twenty types) that we call “vitamin K-dependent proteins”. Among them, prothrombin stands out, which is the central regulator of the coagulation cascade.

The modification in which vitamin K takes part is irreversible and gives rise to a new amino acid called gamma-carboxyglutamic acid. This amino acid is able to capture calcium ions like tweezers. The protein’s combination with calcium allows it to have special functions, including binding to the outside of cell membranes or to certain cell receptors, depending on the calcium concentration.

Mammals are not the only animals that use vitamin K. Going a step further in evolution, the mollusc Conus textile uses vitamin K-dependent neurotoxins to hunt its prey. And although the shell in the photo looks harmless, be careful, as more than thirty fatal poisonings have been described because of its bites.

Vitamin K-dependent tissue repair systems

For those of us who work in this area, it was a surprise when, in the 1990s, a new vitamin K-dependent protein was isolated, very similar to coagulation proteins, capable of activating a family of cell receptors related to those of growth hormones. .

This protein, GAS6, and its partner in regulating clotting, protein S, are able to help immune cells repair damaged tissue.

Its mechanism of action is explained in two steps. What they do to regulate inflammation is help eliminate cells that are in the process of irreversible death and regenerate new cells. Our studies showed that, in addition, they induced fibrosis in organs such as the liver, a very important process to respond to chemical and nutritional damage, such as alcohol, certain diets or toxic substances.

Damage to the cells that make up our organs, accumulated over the years of life, is part of the aging process. Therefore, repair systems such as those represented by these vitamin K-dependent proteins increase in importance with age.

To maintain healthy aging, several scientists have proposed increasing vitamin K intake in the elderly. This can prevent vessel calcification, improve bone health and strengthen tissue repair systems.

In fact, vitamin K deficiencies are very rare in humans and mostly occur in newborns, as vitamin K hardly crosses the placental barrier.

For this reason, at birth, the deficiency is compensated by providing a dose of vitamin K to prevent possible bleeding, which is rare, but with devastating consequences. In Europe it has been done for over 50 years for almost all newborns.

More spinach, cabbage and chard

In adults, vitamin K deficiencies occur only when there are disturbances of intestinal absorption. This is because the intestinal flora itself produces the precursors of vitamin K, so a varied diet is enough to cover the daily need for this micronutrient.

However, for these new functions related to aging, such as the reduction of osteoporosis and vessel calcification, increasing the intake of vitamin K through the consumption of foods rich in it (spinach, chard, kale and green leafy vegetables in general) could improve health .

And although there is still much to be investigated, it seems that to these advantages we would add the maintenance of inflammation repair and regulation systems.