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Vitamin B6

There are six forms of vitamin B6 [Vitamers]

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Vitamin B6

Vitamin B6 exists in 6 forms128,129 in nature and these are called B6 vitamers:

These include the phosphate derivatives --- numbers 4, 5, 6 [below].

  1. Pyridoxal [PL]
  2. Pyridoxamine
  3. Pyridoxine
  4. Pyridoxal 5’ phosphate [PLP]
  5. Pyridoxamine 5’ phosphate
  6. Pyridoxine 5’ phosphate
  • Vitamin B6 is necessary for a wide range of reactions to metabolize proteins, carbohydrates and fats129.
  • Pyridoxal 5’ phosphate [PLP] is the active conenzyme form in human metabolism129.
  • The main dietary form of B6 is pyridoxine which is ultimately converted to pyridoxal 5’ phosphate.
  • In fact each of the B6 vitamers are ultimately converted to pyridoxal 5’ phosphate.

AGES and ALEs --- Destructive glycation and lipid peroxidation

  • Advanced glycation end-products [AGEs] occur when glucose reacts with proteins causing cross-linking of these proteins resulting in irreversible damage to sensitive proteins such as collagen, elastin, haemoglobin, receptors [RAGE] and cell structures.
  • Receptors for AGEs are called RAGEs
  • The best known AGE is HbA1c which is glycated haemoglobin [US hemoglobin] used to assess if diabetic control is adequate.
  • Glycation of proteins is a big danger for diabetics. In fact, aging occurs at an accelerated rate in type 2 diabetics135.  
  • Glycation is also an important process in aging that causes wrinkling of our skin.
  • Pyridoxamine is a potent inhibitor of both advanced glycation end-products [AGEs] and advanced lipoxidation end products [ALEs]130.
  • Pyridoxamine in particular has shown potential in the treatment of diabetes and atherosclerosis131.
  • Glycation of proteins [AGEs] and lipids [ALEs] occur in the aging process and pyridoxamine may have a role here.

Alzheimer's Disease

  • It is suspected that glycation either plays a significant or perhaps a central role in the development of age-related dementias and in Alzheimer's disease133,134.
  • Glycation can cause proteins to clump within neurons impairing critical cellular processes.
  • Extracellular glycation can lead to significant oxidative stress on the neurons and can trigger toxic inflammatory process through the release of cytokines.

Peripheral Neuropathy

  • According to Jennifer Jamison’s text on nutrition and dietary supplements, ‘Vitamin B6 toxicity manifests as sensory peripheral neuritis … Chronic puridoxine intake may cause sensory neuropathy by exceeding the liver’s ability to phosphorylate pyridoxine to the active coenzyme pyridoxal phosphate130.’ Thus peripheral neuropathy can be avoided by supplementing with Pyridoxal 5’ phosphate [PLP]130,132.
  • Unlike pyridoxine [the standard form of vitamin B6], pyridoxamine can be taken in high doses without concern for peripheral neuropathy.
  • Some have argued that pyridoxamine should be the only form of vitamin B6 that should be used in supplements

QuickGuide Topic References

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QuickGuide Topic References

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pyridoxal 5'-phosphate