The role of group B vitamins in energy exchange

The role of group B vitamins in energy exchange

B vitamins are a complex of water -soluble nutrients that play a critical role in maintaining health and well -being. They are inextricably linked with energy metabolism, that is, the process of converting the food that we consume, into the energy necessary to maintain life and fulfill everyday tasks. Each vitamin of group B performs a unique function in this process, and their interaction provides optimal effectiveness.

Tiamin (Vitamin B1)

Tiamin, also known as Vitamin B1, is a key cofactor for several enzymes playing a decisive role in carbohydrate metabolism. It is involved in the decarboxylation of alpha coat acids, which is an important stage in the cycles of Krebs and the pentosophosphate path.

• Carboxylation of alpha coat acids: Thiaminpyrophosphate (TPF), the active form of thiamine, is a coherent for pyruvate dehydrogenase, alpha-ketoglutaratratodehydrogenase and transcetolasis. Piruvat dehydrogenase converts pyruvat to acetyl-koa, which then enters the Crebs cycle. Alfa-Ketoglutaratiratradhydrogenase catalyzes the decarboxylation of alpha-ketoglutarate to succinyl-Coa in the Crebs cycle. Transchatolase is involved in the pentosophosphate path, which produces NASFN (necessary for recovery) and ribozo-5-phosphate (necessary for the synthesis of nucleotides).

• Clinical manifestations of thiamine deficiency: Tiamine deficiency can lead to various states, such as Beri Berie and Vernika-Korsakov syndrome. Beri-Bury is characterized by neurological and cardiovascular disorders, such as muscle weakness, peripheral neuropathy, cardiomegaly and heart failure. Vernika-Korsakov syndrome, more often found in people who abuse alcohol, manifested by confusion, ataxia and ophthalmoplegia. This is due to damage to certain areas of the brain due to thiamine deficiency.

• Tiamin sources: Good sources of thiamine are whole grains, enriched cereals, meat (especially pork), fish, legumes and nuts.

• Factors affecting the assimilation of thiamine: Some factors can affect the absorption of thiamine, including alcohol use, the presence of thiaminases (enzymes that destroy thiamine) in raw fish and mollusks, as well as the use of some drugs.

Riboflavin (vitamin B2)

Riboflavin, or vitamin B2, is the predecessor of two important coofers: Flavmononucleotide (FMN) and Flavideninindinucleotide (FAD). These coofers are involved in many redox reactions that are critical for energy metabolism.

• FMN and FAD in redox reactions: FMN and FAD are prosthetic groups for many enzymes called flavoproteins. These enzymes are involved in the transfer of electrons in various metabolic tracks, including the Krebs cycle, oxidative phosphorylation and beta-oxidation of fatty acids. For example, succinate dehydrogenase, the enzyme of the Krebs cycle, uses FAD to oxidize the succinate to fumarat. NAPD dehydrogenase, component of the I respiratory chain complex, uses the FMN to transfer electrons from NAPN to Kilikhinon.

• Riboflavin and antioxidant protection: Riboflavin also plays a role in antioxidant protection. It is necessary for the work of glutathioneuctasis, an enzyme that supports the restored form of glutathione, an important antioxidant.

• Clinical manifestations of riboflavin deficiency: Riboflavin deficiency, known as ariboflavinosis, can manifest itself with chelosis (cracks in the corners of the mouth), glossitis (inflammation of the tongue), seborrheic dermatitis and anemia.

• Riboflavin sources: Good sources of riboflavin are dairy products, meat, eggs, green leafy vegetables, enriched cereals and mushrooms.

• Factors affecting the assimilation of riboflavin: Riboflavin is sensitive to light, so the products containing riboflavin should be stored in a dark place. The absorption of riboflavin can be disturbed by some drugs, such as tricyclic antidepressants and some antitumor drugs.

Niacin (Vitamin B3)

Niacin, or vitamin B3, exists in two forms: nicotinic acid and nicotinamide. He is the predecessor of two important coofers: nicotinindinindinucleotide (above) and nicotinydenindinindinucleotidfosphate (NAS). Above and NADF are involved in hundreds of enzymatic reactions, especially in redox processes necessary for energy metabolism.

• Above and NADF in redox reactions: Over the act of electrons in the catabolic tracks, such as glycolis, the Krebs and beta-oxidation of fatty acids. It accepts electrons and becomes NADN, which then transmits electrons to the respiratory chain for the production of ATP. NAS, on the other hand, mainly participates in the anabolic tracks, such as the synthesis of fatty acids and nucleotides. It acts as an electron donor in these processes.

• Niacin and a decrease in cholesterol level: Niacin in high doses can reduce LDL cholesterol (poor cholesterol) and triglycerides, as well as increase the level of HDL cholesterol (good cholesterol). However, the use of niacin in such doses should be carried out under the supervision of a doctor, since it can cause side effects, such as redness of the skin, itching and impaired liver function.

• Clinical manifestations of niacin deficiency: Niacin deficiency leads to Pellagra, which is characterized by “three D”: dermatitis, diarrhea and dementia. Dermatitis usually manifests itself in the form of a symmetrical rash in areas of skin exposed to sunlight.

• Sources of Niacin: Good sources of niacin are meat, poultry, fish, enriched cereals, nuts and legumes. Niacin can also be synthesized in the body of the Tryptophan amino acid, but this process is not very effective.

• Factors affecting the assimilation of niacin: The assimilation of niacin can be disturbed by some drugs such as isoniazide (used to treat tuberculosis).

Pantotenic acid (vitamin B5)

Pantotenic acid, or vitamin B5, is a component of coherent A (COA), which plays a central role in energy metabolism. The COA is involved in the transfer of acyel groups, which is necessary for many metabolic processes, including the Crebs cycle, synthesis and oxidation of fatty acids, as well as cholesterol synthesis.

• KOA in the Crebs cycle: KOA is necessary for the formation of acetyl-koa from Piruvat, which then enters the Crebs cycle. He also participates in the formation of succinyl-cooa from alpha-ketoglutarate.

• Coa in the synthesis and oxidation of fatty acids: KOA is involved in the activation of fatty acids for beta-oxidation. Activated fatty acids associated with the COA are transported to mitochondria, where they are oxidized for energy production. COA is also necessary for the synthesis of fatty acids.

• Clinical manifestations of pantothenic acid deficiency: The deficiency of pantothenic acid is rare, since it is widespread in food products. However, experimental deficiency can cause fatigue, headache, insomnia and numbness of the limbs.

• Sources of pantothenic acid: Good sources of pantothenic acid are meat, poultry, fish, eggs, milk, vegetables (especially broccoli, avocados and sweet potatoes), mushrooms and whole grains.

• Factors affecting the absorption of pantothenic acid: The absorption of pantothenic acid can be disturbed by some drugs such as anticonvulsant drugs.

Pyridoxine (vitamin B6)

Pyridoxine, or vitamin B6, is a group of compounds, including pyridoxine, pyridoxal and pyridoxamine. The active form of vitamin B6 is pyridoxal-5′-phosphate (PLF), which acts as a coherent for more than 100 enzymes involved in the metabolism of amino acids, carbohydrates and lipids.

• PLF in amino acid metabolism: PLF plays a key role in transaminating, deaminating, decarboxylation and amino acid racemization. These reactions are necessary for the synthesis of non -irregular amino acids, neurotransmitters (such as serotonin, dopamine and gamut) and hem.

• PLF in carbohydrate metabolism: PLF is involved in glycogenolysis, the process of splitting glycogen to glucose. It is a coherent for glycogen phosphorylase, an enzyme that catalyzes this process.

• PLF in lipid metabolism: PLF is necessary for the synthesis of sphingolipids, important components of cell membranes.

• Clinical manifestations of pyridoxine deficiency: A deficiency of pyridoxine can cause various symptoms, including depression, confusion, convulsions, dermatitis, anemia and peripheral neuropathy.

• Sources of pyridoxine: Good sources of pyridoxine are meat, poultry, fish, eggs, vegetables (especially potatoes, carrots and spinach), fruits (especially bananas and avocados) and whole grains.

• Factors affecting the assimilation of pyridoxine: The assimilation of pyridoxine can be disturbed by some drugs, such as isoniazide, penicilllammin and oral contraceptives.

Biotin (Vitamin B7)

Biotin, or vitamin B7, acts as a coherent for carboxylase, enzymes that catalyze the addition of carbon dioxide to various substrates. These enzymes play an important role in the metabolism of carbohydrates, fats and proteins.

• Carboxylase dependent on biotin: Four main carboxylasis, dependent on biotin, include:

  • Pyrivatarboxylase: Catalizes pyruvate carboxylation to oxaloacetate necessary for gluconeogenesis (synthesis of glucose from non -ahard sources) and replenishment of oxaloacetate reserves in the frees cycle.
  • Acetyl-koa-carboxylase: Catalizes carboxylation of acetyl-koa to a little-koa, the first step in the synthesis of fatty acids.
  • Propionil-Coa-carboxylase: Catalizes the carboxylation of propionil-koa to methylmalonalin-koa, which is necessary for the metabolism of some amino acids and fatty acids with an odd number of carbon atoms.
  • Beta-methylcrotonel-koa-carboxylase: Catalizes carboxylation of beta-methylcrotonel-cooa to beta-methylglutakonil-koa, necessary for leicin catabolism.

• Clinical manifestations of biotin deficiency: Biotin’s deficiency is rare, but can occur when using a large amount of raw egg proteins (which contain avidine, associated with biotin and prevents its absorption) or for genetic disorders affecting the activity of biotinidase (enzyme that releases biotin from food proteins). Symptoms of biotin deficiency may include dermatitis, alopecia (hair loss), neurological disorders and immune dysfunction.

• Sources of biotin: Good sources of biotin are meat, poultry, fish, eggs, dairy products, nuts, seeds and some vegetables (especially sweet potatoes and spinach).

• Factors affecting the assimilation of biotin: The use of a large amount of raw egg proteins can prevent the absorption of biotin. Some drugs, such as antibiotics, can also affect the assimilation of biotin, changing the intestinal microflora.

Folic acid (vitamin B9)

Folic acid, or vitamin B9, is an important vitamin necessary for the synthesis of DNA and RNA, as well as for amino acid metabolism. The active form of folic acid is a tetrahydrofolat (TGF), which acts as a coherent for enzymes involved in the transfer of single -carbon fragments.

• TGF in DNA and RNA synthesis: TGF is necessary for the synthesis of purines and pyrimidins, construction blocks of DNA and RNA. It is involved in the reactions necessary for the transformation of deoxyuridinmonophosphate (DUMF) into deoxytimidinemonophosphate (DTMF), which is necessary for the synthesis of DNA.

• TGF in amino acid metabolism: TGF is involved in the metabolism of homocysteine, an important amino acid. It is necessary to convert homocysteine ​​into methionine, a reaction catalyzed by methioninsyntase, an enzyme, which also requires vitamin B12.

• Clinical manifestations of folic acid deficiency: Folic acid deficiency can lead to megaloblastic anemia, characterized by abnormally large and immature red blood cells. Folic acid deficiency during pregnancy can increase the risk of defects in the nerve tube in the fetus, such as the clever spine.

• Folic acid sources: Good sources of folic acid are green leafy vegetables (especially spinach, Romen and broccoli salad), legumes, citrus fruits, enriched cereals and liver.

• Factors affecting the absorption of folic acid: The absorption of folic acid can be disturbed by some drugs such as methotrexate, sulfasalazine and anticonvulsant drugs. The use of alcohol can also prevent the absorption of folic acid.

Cobalamin (vitamin B12)

Cobalamin, or vitamin B12, is an important vitamin necessary for the normal function of the nervous system, the synthesis of DNA and the formation of red blood cells. It acts as a coherent for two enzymes: methyoninsyntase and methylmalolin-coo-mutase.

• Methioninsintase: Methyoninsyntase catalyzes the transformation of homocysteine ​​into methionine, a reaction that also requires folic acid. This reaction is necessary for the synthesis of S-adenosylmetionine (itself), an important donor of methyl groups in numerous metabolic reactions.

• Methilmalonil-Coa-Mutase: Methylmalonil-CoA Mutase catalyzes the transformation of methylmalonil-cooa into a succinyl-cooa, which enters the Crebs cycle. This reaction is necessary for the metabolism of some amino acids and fatty acids with an odd number of carbon atoms.

• Clinical manifestations of cobalamine deficiency: Cobalamine deficiency can lead to megaloblastic anemia, neurological disorders (such as peripheral neuropathy, dementia and demyelinization of nerve fibers) and an increased level of homocysteine ​​in the blood. Cobalamine deficiency is more often found in older people, vegans and people with absorption disorders (for example, with atrophic gastritis or after stomach resection).

• Sources of cobalamine: Vitamin B12 is contained only in animal products, such as meat, poultry, fish, eggs and dairy products. Vegans need to take vitamin B12 additives or use enriched products to ensure adequate consumption of this vitamin.

• Factors affecting the assimilation of cobalamine: The assimilation of cobalamine requires a complex process, which includes the release of cobalamin from food, binding with the internal factor (protein produced by the stomach cells), the absorption of the complex of the internal factor and cobalamine in the iliac intestine. Violations in any of these stages can lead to a deficiency of cobalamin. Some drugs, such as proton pump inhibitors and metformin, can also affect the absorption of cobalamin.

In conclusion, group B vitamins play an essential role in energy metabolism, participating in various metabolic tracks necessary for converting food into energy. The deficiency of any of these vitamins can lead to a wide range of clinical manifestations affecting the nervous system, cardiovascular system, immune system and other organs and tissues. Providing adequate consumption of group B vitamins with food or using additives is important for maintaining health and well -being.