Vitamin B-complex is a group of water-soluble vitamins. Most of B-complex vitamins occurs in nature in the bound form within the cells of fruits and vegetables or animal tissues. Vitamin B-complex is not stored in appreciable amounts in the body tissues except vitamin B12. Excretion of vitamins occurs in the kidneys. Because they are water-soluble and therefore easily lost in the urine, B vitamins must be obtained from the diet. Unlike the lipid-soluble vitamins, they cannot be stored in the body fat.

B vitamins are generally coenzymes in the energy metabolism. B vitamins are some of the most important factors in mental health. The brain requires lots of the B vitamins to repair and permanent maintenance of proper neurotransmitter and adrenal function. Stress causes the B vitamins to be quickly depleted.

Below is the list of substances referred to as Vitamin B-complex based on their pharmacological action:

  • 4-Aminobenzoic Acid - Also called PABA; used to be common in sunscreening agents until found to also be a sensitizer. The potassium salt is used therapeutically in fibrotic skin disorders.
  • Acetylcarnitine - A substance which can act as a carrier for acetyl groups across the mitochondrial membrane in mammalian liver; participates in the oxidation of fats.
  • Biotin - A water-soluble, enzyme co-factor present in minute amounts in every living cell. It occurs mainly bound to proteins or polypeptides and is abundant in liver, kidney, pancreas, yeast, and milk.
  • Carnitine - Constituent of striated muscle and liver. It is used therapeutically to stimulate gastric and pancreatic secretions and in the treatment of hyperlipoproteinemias.
  • Flavin Mononucleotide - the principal form in which riboflavin is found in cells and tissues.
  • Folic Acid - A substance that timulates the formation of blood cells. It is present in the liver and kidney and is found in mushrooms, spinach, yeast, green leaves, and grasses; used in the treatment and prevention of folate deficiencies and megaloblastic anemia.
  • Fursultiamin - A Compound used for therapy of thiamine deficiency.
  • Hydroxocobalamin - Injectable form of vitamin B12 that has been used therapeutically to treat vitamin B12 deficiency.
  • Inositol - An isomer of glucose that has traditionally been considered to be a B vitamin although it has an uncertain status as a vitamin and a deficiency syndrome. Inositol phospholipids are important in signal transduction.
  • Leucovorin - The active metabolite of folic acid; used principally as its calcium salt as an antidote to folic acid antagonists which block the conversion of folic acid to folinic acid.
  • Niacin - A water-soluble vitamin required for the formation of coenzymes NAD and NADP. It has pellagra-curative, vasodilating, and antilipemic properties.
  • Niacinamide - An important component of the coenzyme NAD; used in the prevention and/or cure of blacktongue and pellagra; must be supplemented through dietary intake.
  • Pantothenic Acid - Vitamin B5; it is incorporated into Coenzyme A and protects cells against peroxidative damage by increasing the level of glutathione.
  • Pyridoxal - The 4-carboxyaldehyde form of vitamin B6 which is converted to pyridoxal phosphate.
  • Pyridoxal Phosphate - The active form of vitamin B6 serving as a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, aminolevulinic acid. During transamination of amino acids, it is transiently converted into pyridoxamine phosphate.
  • Pyridoxamine - The 4-aminomethyl form of vitamin B6. During transamination of amino acids, pyridoxal phosphate is transiently converted into pyridoxamine phosphate.
  • Pyridoxine - The 4-methanol form of vitamin B6 which is converted to pyridoxal phosphate.
  • Riboflavin - Vitamin B2; found in milk, eggs, malted barley, liver, kidney, heart, and leafy vegetables. The richest natural source is yeast. It occurs in the free form only in the retina of the eye, in whey, and in urine; its principal forms in tissues and cells are as flavin mononucleotide and flavin-adenine dinucleotide.
  • Thiamine Monophosphate - The monophosphate ester of thiamine. Synonyms: monophosphothiamine; vitamin B1 monophosphate.
  • Thiamine Pyrophosphate - The coenzyme form of vitamin B1 present in many animal tissues.
  • Thiamine Triphosphate - The triphosphate ester of thiamine. In Leigh's disease, this compound is present in decreased amounts in the brain due to a metabolic block in its formation.
  • Vitamin B12 - A cobalt-containing coordination compound produced by intestinal micro-organisms and found also in soil and water. Higher plants do not concentrate vitamin B 12 from the soil and so are a poor source of the substance as compared with animal tissues.
  • Vitamin B6 - Vitamin B6 refers to several compounds (pyridoxal, pyridoxine, pyridoxamine) that are efficiently converted by the body to pyridoxal phosphate which is a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, and aminolevulinic acid. Pyridoxine and vitamin B6 are not synonyms. Most of vitamin B6 is eventually degraded to pyridoxic acid and excreted in the urine.