Vitamin B12, also known as cobalamin, is crucial for our body’s vitality. Given its essential nature and scarcity in nature, it is clear why it is such an important dietary supplement.
Vitamin B12 is found almost exclusively in animal-based foods, with the exception of a few types of algae in significantly smaller amounts.
Although B vitamins, including B1, B2, B3, B5, B6, B7, B9, and B12, vary in their structure and biochemical roles, they fall under the same group as they often come from similar dietary sources and are all water-soluble..
Vitamin B12 has a range of important functions in our body, with its most well-known roles being in the health of the nervous system and brain development, cardiovascular health, DNA synthesis and the breakdown of homocysteine.
Additionally, vitamin B12 plays a crucial role in the production of red blood cells and DNA synthesis.
Vitamin B12, along with vitamins B1 (thiamine) and B6 (folate), is considered a neurotropic vitamin.
It is well known that vitamin B12 plays a significant role in the functioning of the nervous system, and a deficiency in vitamin B12 can lead to diseases and conditions associated with the degeneration of the nervous system.
The role of vitamin B12 in the nervous system is primarily in the DNA synthesis of oligodendrocytes, cells in the central nervous system responsible for producing myelin. Myelin forms the myelin sheath, which extends along nerve fibers and provides an insulating layer, thereby accelerating signal transmission through nerve fibers. Damage to the myelin sheath causes slowed signal transmission and damage to the nervous system.
Vitamin B12 has a positive effect on nervous system damage, and it has been proven that vitamin B12 supplementation can lead to the disappearance or reduction of symptoms associated with nerve damage (such as tingling and numbness).
Vitamin B12 is responsible for the breakdown of homocysteine, and elevated levels of homocysteine in the blood serum can be an indicator of vitamin B12 deficiency.
Increased levels of homocysteine are associated with a higher risk of heart attack.
Akumulacija homocisteina u stanici dokazano utječe na popravak DNA, apoptozu* te sintezu inflamatornih citokina.
Vitamin B12 was first isolated in 1948 as a treatment for megaloblastic anemia, a condition that causes abnormalities in the shape, size, and maturity of red blood cells. Megaloblastic anemia is the most common hematological condition associated with vitamin B12 deficiency.
*Apoptosis – programmed cell death, occurring when a cell is damaged or in development (e.g., the cells between fingers in a developing fetus).
The causes of vitamin B12 deficiency can be linked to several factors, including:
Vitamin B12 deficiency may present with the following symptoms:
Since vitamin B12 is water-soluble, any excess is generally excreted from the body through urine. Therefore, even high doses of vitamin B12, whether taken as supplements or from dietary sources, do not pose a risk of vitamin B12 toxicity.
Vitamin B12 is primarily available in animal-based foods.
Namirnice koje sadržavaju vitamin B12 su:
Additionally, many other food products are fortified with vitamin B12, such as cereals, plant-based milks, and yogurts.
Vitamin B12 in supplements and food comes in several forms. The metabolically active forms of vitamin B12 are methylcobalamin and 5-deoxyadenosylcobalamin.
Supplements most commonly contain cyanocobalamin, but they can also include adenosylcobalamin, methylcobalamin, or hydroxocobalamin. It is important to note that there is no evidence suggesting that any of these forms is better absorbed when used in supplementation.
Besides oral supplements, vitamin B12 can also be administered intravenously, usually when a person has a condition that impairs the absorption of vitamin B12 through the digestive system. This treatment requires a doctor’s prescription. For most people, oral supplements are effective.
