The vitamin B-complex

The vitamins from the vitamin B complex are water-soluble vitamins. The vitamins in this complex were originally grouped together because they largely share the same functions; the vitamins serve as important coenzymes needed to convert carbohydrates into energy (carbohydrates are then converted into glucose). Additionally, the vitamins are needed in the body for the metabolism of proteins and fats.
The coenzymes are essential for specific reactions; without the presence of B vitamins as coenzymes, these specific reactions do not occur. This means that it is not possible to convert carbohydrates into energy (in the absence of B vitamins) and that the absorption of proteins and fats is negatively affected.
The following vitamins play an important role in the use of food energy: thiamine (B1), riboflavin (B2), niacin (B3), pyridoxine (B6), pantothenic acid (B5), and biotin (B8).
The vitamins folic acid (B11), cobalamin (B12), and choline (B4) are important for cell maintenance and growth and for blood cell synthesis.

Vitamin B1 plays an important role in carbohydrate metabolism. Vitamin B1 is a component of the coenzyme thiamine pyrophosphate. This coenzyme is necessary to convert carbohydrates into energy. Additionally, the coenzyme is important for the metabolism of fatty acids, nucleic acids, amino acids, and steroids. The need for thiamine is not the same for every animal; this is because the need for the vitamin depends on the amount of carbohydrates in the animal's diet. The more carbohydrates the diet contains, the higher the need for thiamine.

Another important role of vitamin B1 is the functioning of the central nervous system. The central nervous system uses the energy released when carbohydrates are converted into glucose. When a dog or cat does not get enough thiamine, this can negatively affect the functioning of the central nervous system, as there is insufficient energy available.

Like vitamin B1, vitamin B2 is needed to convert carbohydrates into energy. Riboflavin is a component of two different coenzymes. These coenzymes, in turn, are necessary to release energy from nutrients: proteins, fats, and carbohydrates.
Riboflavin can be synthesized in the large intestine, but not all animals are able to synthesize the vitamin themselves; dogs and cats can. The amount of riboflavin that can be synthesized depends on the species and the amount of carbohydrates the animal has consumed through its diet. However, it is still unknown to what extent riboflavin synthesis contributes to the vitamin’s nutritional requirements in dogs and cats.

Riboflavin plays a role in the production of red blood cells. These red blood cells serve as carriers of oxygen to all parts of the body. The vitamin is also needed for the production of antibodies that protect the body against pathogens (disease-causing agents).

Furthermore, vitamin B2 plays an important role in the growth and repair of DNA. This helps improve wound healing, slows the aging process, and can reduce the risk of certain diseases.

When a dog or cat consumes niacin through their diet, it must first be converted into an active form: niacinamide. Once converted into the active form, the nutrient is needed for two coenzymes: nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP). Both coenzymes are necessary for the metabolism of proteins, fats, and carbohydrates so that the nutrients can be utilized. This vitamin helps break down fatty acids so the body can absorb them. As a result, niacin contributes to healthy skin and a shiny coat.

Another role of niacin relates to hormones; vitamin B3 is needed for the synthesis of various hormones. Vitamin B3 contributes to the production of two hormones: antidiuretic hormone or vasopressin (which supports proper kidney function) and corticotropin-releasing hormones (which promote the release of corticosteroids that can reduce stress levels).
In addition, niacin is necessary for the synthesis of the hormones estrogen and testosterone.
Finally, vitamin B3 is essential for the growth of puppies and kittens. In this case, vitamin B3 supports the production of growth hormone, which helps a puppy or kitten grow into a strong and healthy adult animal.

Vitamin B3 is present in both plant and animal sources. However, vitamin B3 in plant material is often in a bound form that is not available for absorption; vitamin B3 found in animal sources is often in an unbound form, which is available for absorption.

Dogs have a lower requirement for vitamin B3 than cats. This is because dogs can synthesize niacin. Dogs can convert tryptophan into niacin. In cats, tryptophan is converted into acetyl coenzyme A. For this reason, cats have a higher need for vitamin B3 and must obtain the full recommended amount of niacin through their diet.

Pyridoxine is a vitamin consisting of three different compounds: pyridoxine, pyridoxal, and pyridoxamine. Pyridoxal, the compound that is part of the coenzyme pyridoxal 5 phosphate, is the biologically active form.

Vitamin B6 is essential for protein synthesis (the creation of proteins in the body). As a result, vitamin B6 contributes to optimal growth of puppies and kittens. Furthermore, the vitamin is needed to secrete hormones required for important physiological processes (metabolism) in the body.

Pyridoxine is not only necessary for protein synthesis but also for the production of hormones and neurotransmitters. Neurotransmitters are substances that transmit signals within nerve cells.

Pyridoxine is needed for the absorption of fats and proteins by the body. The vitamin ensures that nutrients are converted into substances the body can absorb. Moreover, vitamin B6 is involved in more than 50 reactions in the body's cells. These reactions relate to:

• Transamination: the conversion of fatty acids or amino acids into other amino acids.
• Decarboxylation: this involves the removal of a carbon from an amino acid chain, shortening it.

Furthermore, pyridoxine plays an important role in maintaining the proper balance between potassium and salt. This, in turn, regulates water balance in the body.

Finally, vitamin B6 plays a role in various processes in the body. It is necessary for the production of red blood cells, the synthesis of DNA and RNA, and the normal functioning of the brain. It also supports an optimally functioning immune system because it is needed for the formation of antibodies.

Like the aforementioned B vitamins, pantothenic acid is a component of two different coenzymes, namely acetyl coenzyme A and ACP. Acetyl coenzyme A is a coenzyme essential for the metabolism of body tissues. Both coenzymes are required for a wide range of metabolic pathways related to the metabolism of proteins, fats, and carbohydrates; they also play a role in the synthesis of lipids (fats and fat-like substances), hormones, neurotransmitters, and hemoglobin.

Pantothenic acid also contributes to an optimally functioning immune system. This is because pantothenic acid contributes to the production of antibodies.

As you have already read, the vitamins from the vitamin B complex are all necessary for carbohydrate metabolism, including vitamin B8. Vitamin B8 is not only needed for carbohydrate metabolism but is also essential for the metabolism of proteins and fats, the formation of healthy connective tissue, and the formation of cells.
Furthermore, biotin plays a role in maintaining healthy skin and coat. It is necessary for growth, muscle formation, and the nutrient is essential for the body to use glucose as an energy source.

Biotin is also involved in fatty acid synthesis and the breakdown of amino acids. Biotin is needed for the normal synthesis of long-chain unsaturated fatty acids and for the metabolism of essential fatty acids. The vitamin is required for the normal function of immune cells that actively accumulate biotin. T and B lymphocytes depend on the supply of biotin.

Folic acid is an important nutrient for the formation of red blood cells. Vitamin B11 is also necessary for the normal functioning of metabolic processes.
Finally, folic acid is essential for the repair and production/creation of cells and tissues.

Cobalamin is an important part of various enzyme systems, enzyme systems required to carry out a large number of metabolic functions; most reactions/functions involve the synthesis or transfer of carbon units.
The main functions of vitamin B12 are the metabolism of proteins and nucleic acids. However, the nutrient is also important for the metabolism of both fats and carbohydrates. Furthermore, cobalamin is needed for the formation of proteins from amino acids.

Vitamin B12 is also a component of a coenzyme. This coenzyme is required for two enzymes: methionine synthase and methylmalonyl-CoA mutase. The enzyme methionine synthase is needed for the synthesis of methionine (an essential amino acid). However, the formation of methionine cannot occur without folic acid, vitamin B11.

Choline is necessary for the maintenance and development of cell structure. Choline is an important component of lecithin. Lecithin is a substance that is part of animal cell membranes.
Another function of choline is ensuring the normal maturation of the cartilage matrix. The cartilage matrix is essential for a strong skeleton.

Furthermore, vitamin B4 plays an important role in fat metabolism in the liver. Here, the vitamin helps reduce the risk of abnormal fat accumulation (fatty liver). It does this by regulating fat and cholesterol metabolism.

Vitamin B4 is a building block of acetylcholine. Acetylcholine is a neurotransmitter. This neurotransmitter has various functions. It is needed for regulating heart rate, essential for muscles to enable contractions, plays a role in dilating blood vessels, and other processes.

Finally, choline plays a role in the synthesis of methionine and creatine. Without choline, the body cannot synthesize these amino acids.
Furthermore, choline is a source of methyl groups, contributing to the synthesis of purine and pyrimidine, as methyl groups are needed for their synthesis; purine and pyrimidine are in turn necessary for the formation of DNA.

Glossary
Antibodies: substances (white blood cells) that protect the body against pathogens/disease-causing agents.

B-lymphocytes: part of the immune system, they produce antibodies.

Co-enzyme: a small organic molecule required for an enzyme to perform its function.

Dilate: the widening of blood vessels.

Hemoglobin: a protein in the blood that transports oxygen throughout the body.

Cartilage matrix: the cartilage matrix consists of collagen, hyaluronic acid, proteoglycans, and a small amount of glycoproteins.

Methionine synthase: is an enzyme dependent on cobalamin, folic acid, and pyridoxine.

Nucleic acids: complex organic acids found in the cell nucleus that form chromosomes and genes – these can be distinguished into RNA and DNA.

Steroids: a group of organic compounds. They are a group of fat-soluble hormones.

Synthesis: a combination of various substances or nutrients from which a new substance or nutrient is formed.

T-lymphocytes: part of the immune system, they are defense cells.