Vitamin B6

Vitamin B6 is the collective name for three similar chemical compounds, which are all precursors of the activated vitamin pyridoxal phosphate. These are pyridoxine, pyridoxal, and pyridoxamine; they are vitamins of the B complex. All three materials can be transferred from one another and metabolism have the same biological activity. Humans can not manufacture entirely self cofactor pyridoxal phosphate and is it dependent on the supply of these precursors in the diet, the content thereof is so high that usually there are no symptoms of deficiency.


Vitamin B6 is a derivative of pyridine. Vitamin B6 is as pyridoxine ( an alcohol ), pyridoxamine ( an amine ), pyridoxal ( an aldehyde ) and their phosphoric acid esters, such as pyridoxal phosphate (PLP ), above.

Pyridoxal CAS No.:. 66-72-8

Pyridoxamine CAS No.:. 85-87-0

Physiological function

The phosphorylated vitamin B6 derivatives act as coenzymes in about 100 enzymatic reactions, almost exclusively in the amino acid metabolism. Another important task is performed by the pyridoxal phosphate (PLP or PALP, a pyridoxine derivative) as a cofactor in the synthesis of δ -aminolevulinic acid, an intermediate in the endogenous heme synthesis. Mention may also be the participation of pyridoxal phosphate as a cofactor in the degradation of the " animal starch " ( glycogen).


Vitamin B6 is found in small doses in almost all foods of animal and vegetable origin. Dairy products, liver, poultry and meat, fish, cabbage, green beans, lentils, lettuce, potatoes, whole grain cereals, whole grains, wheat germ, nuts, yeast, wheat beer, avocado and bananas are good sources.


Since vitamin B6 exerts its effects in the metabolism of amino acids, the demand on the supplied protein is dependent. The German Nutrition Society ( DGE) recommends a dose of 0.02 mg / g protein. That would mean a need for men of 1.8 mg and 1.6 mg for women. In case of excessive protein intake, it is assumed that the demand by the specified amount can not be met. Receiving the more proteins of the body, the more vitamin B6 it needs.

Deficiency ( hypovitaminosis )

Because in nearly all foods, vitamin B6 occurs, deficiency symptoms are rare. They occur mostly together with a lack of another water-soluble vitamin and have the following signs:

  • Loss of appetite, diarrhea and vomiting
  • Dermatitis, growth retardation and anemia
  • Degeneration of the peripheral nerves with paralysis and afferent ataxia, that is, perceptions of the body are no longer transmitted to the brain so that it can no longer control the necessary motions of the body properly
  • Convulsions at irregular intervals
  • Microcytic, hypochromic anemia ( disorder of heme biosynthesis )
  • Seborrhea -like damage to the eyes, nose and mouth (T- Zone)
  • Cheilosis and glossitis
  • Anxiety disorders

Vitamin B6 in histamine intolerance

As therapy at very high Glutaminsäurewerten ( glutamate ) in the blood findings, such as can occur for example in China -Restaurant Syndrome, or Exkzemen and / or histamine intolerance, recommends Prof. Reinhart Jarisch a vitamin B6 administration in the order of 0.5 mg / kg of body weight per day. This also promotes the body's synthesis of diamine oxidase (DAO ) and fight so cause the effects of histamine intolerance. This view is controversial and is not shared by all doctors. The reference intervals (normal values) for glutamic acid in the blood findings are in infants 20-107 micromol / ml, in children 18-65 micromol / ml and in adults 28-92 micromol / ml.

Consequences of an overdose ( hypervitaminosis )

Chronic hypervitaminosis occurs only through daily intake of more than 500 mg. This dose can not be achieved by natural intake, but only by supplementation. She led a small number of cases to neurotoxicity and photosensitivity. Neurotoxicity has a peripheral sensory neuropathy with ataxic gait disturbances, reflex failures and disturbances of touch, vibration, and temperature perception result. The occurrence of a rash, such as acne medicamentosa is described. In infants, a gram of pyridoxine per day leads to tachycardia, peripheral circulatory disorders and areflexia. These symptoms largely disappear after discontinuation of pyridoxine. A 2002 study with 12 subjects reported that in the daily intake of 250 mg of pyridoxine at bedtime after three days manifested a stronger dream experience.