The vitamin B complex

The vitamins in the vitamin B complex are water-soluble vitamins. The vitamins in this complex were originally grouped together because, to a large extent, they have the same functions; the vitamins serve as important coenzymes needed to convert carbohydrates into energy (carbohydrates are then converted into glucose). In addition, these vitamins are needed in the body for the metabolism of proteins and fats.
The coenzymes are essential for specific reactions; without the B vitamins being present as coenzymes, these specific reactions do not take place. This means that, in the absence of B vitamins, it is not possible to convert carbohydrates into energy, and the absorption of proteins and fats is negatively affected.
The following vitamins play an important role in the utilization 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 maintaining cells, growth, and 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 needed to convert carbohydrates into energy. In addition, 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 greater the need for thiamine.

Another important role of vitamin B1 is supporting the function 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 function of the central nervous system, as insufficient energy is then 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 needed 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 animal 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 dogs' and cats' dietary requirement for the vitamin.

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

Vitamin B2 also plays an important role in the growth and repair of DNA. This contributes to better wound healing, slows the aging process, and may reduce the risk of certain diseases.

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

Another role of niacin is related 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 may reduce stress levels).
Niacin is also needed 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, enabling a puppy or kitten to grow into a strong and healthy adult animal.

Vitamin B3 is found in both plant and animal sources. However, vitamin B3 in plant matter is often in a bound form that is unavailable for absorption; vitamin B3 found in animal sources is often present in an unbound form, which is available for absorption.

Dogs have a lower requirement for vitamin B3 than cats. This is because dogs are able to synthesize niacin. Dogs can convert tryptophan into niacin. In cats, tryptophan is converted into acetyl coenzyme A. For this reason, cats have a higher requirement for vitamin B3; these animals 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 a component of the coenzyme pyridoxal 5-phosphate, is the biologically active form.

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

Pyridoxine is needed not only 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 that the body can absorb. Vitamin B6 also plays a role in more than 50 reactions in the body's cells. These are reactions related to:

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

Pyridoxine also plays an important role in maintaining the proper balance between potassium and salt. This, in turn, supports water regulation in the body.

Finally, vitamin B6 plays a role in various processes in the body. It is needed 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 B vitamins mentioned above, pantothenic acid is a component of two different coenzymes: acetyl coenzyme A and ACP. Acetyl coenzyme A is a coenzyme that is essential for the metabolism of body tissues. Both coenzymes are also needed for a wide range of metabolic pathways involved in 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 by supporting antibody production.

As you may have read earlier, all the vitamins in the vitamin B complex are necessary for carbohydrate metabolism, including vitamin B8. Vitamin B8 is not only needed for carbohydrate metabolism; it is also necessary for the metabolism of proteins and fats, the formation of healthy connective tissue, and cell formation.
Biotin also helps maintain healthy skin and coat. It is needed for growth and 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 an adequate supply of biotin.

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

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

Vitamin B12 is also a component of a coenzyme. This coenzyme is needed 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, methionine cannot be formed without folic acid, vitamin B11.

Choline is needed for the maintenance and formation of cell structures. Choline is an important component of lecithin, which is a substance found in animal cell membranes.
Another function of choline is to ensure normal maturation of the cartilage matrix. The cartilage matrix is essential for a strong skeleton.

Vitamin B4 also plays an important role in fat metabolism in the liver. Here, the vitamin reduces the likelihood 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. For example, it is needed to regulate the heart rate, is necessary for muscle contractions, plays a role in dilating the blood vessels, and is involved in many other processes.

Finally, choline plays a role in the synthesis of methionine and creatine. Without choline, the body cannot synthesize these amino acids.
Choline is also a source of methyl groups, meaning that it contributes to the synthesis of purines and pyrimidines, which require methyl groups for their synthesis; purines and pyrimidines, in turn, are needed for the formation of DNA.

Glossary
Antibodies: substances (white blood cells) that protect the body against pathogens.

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

Coenzyme: a small organic molecule required by an enzyme to perform its function.

Dilate: to widen the 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: an enzyme that depends on cobalamin, folic acid, and pyridoxine.

Nucleic acids: complex organic acids found in the cell nucleus, where they form the chromosomes and genes—they can be divided into RNA and DNA.

Steroids: a group of organic compounds. It is a group of fat-soluble hormones.

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

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