VITAMIN B6

Vitamin B6 is a coenzyme that plays a critical role in many biochemical and physiological processes in the human body, such as amino acid and homocysteine metabolism, glucose and lipid metabolism, neurotransmitter production and DNA/RNA synthesis. Vitamin B6 also takes part in the methylation cycle which is important for gene regulations. The most active form of vitamin B6 is pyridoxal 5'-phosphate, and there is also the pyridoxamine-5'-phosphate coenzyme form. By the way, clinically significant vitamin B6 deficiency is not common (Hellmann, H., & Mooney, S. 2009). In the diet, for food resources of vitamin B6, red and white meat, fish and other seafoods, eggs, carrots, spinach, cauliflower, bananas, avocados and hazelnuts can be preferred.

 

Vitamin B6 and Alkaline Phosphatase (ALPL) Gene Relationship

Alkaline phosphatase (ALPL) enzyme is effective in vitamin B6 metabolism. It plays a role in the hydrolysis of pyridoxal phosphate to pyridoxal. Vitamin B6 is effective in brain health, and its deficiency has been associated with the regulation of brain neurotransmitters and cerebrospinal fluid (CSF). Therefore, the need for vitamin B6 must be met in order to maintain healthy mental functions. Vitamin B6 (pyridoxine) is a type of water-soluble vitamin that has very important functions as a coenzyme in protein metabolism and in the synthesis of neurotransmitters. Pyridoxine can also be found in different forms called pyridoxal and pyridoxamine in the structure of foods. Cofactors such as magnesium and riboflavin (vitamin B2) are required for the conversion of pyridoxine to its active form, pyridoxal phosphate (PLF) (Loes M. et al, 2019).

The table above includes the ALPL gene and its polymorphic allele (rs4654748), which plays a role in vitamin B6 metabolism. As a result of mutations in the ALPL gene, low or complete absence of alkaline phosphatase (ALP) activity can be observed. Since ALP is the enzyme that plays a role in the clearance of vitamin B6, it is related to plasma vitamin B6 level. Namely, in C allele carriers, the lower vitamin B6 level is most likely due to more effective clearance of the vitamin (Tanaka, T. et al., 2009).

 

REFERENCES

Hellmann, H.; Mooney, S. Vitamin B₆: A Molecule for Human Health? Molecules 2010, 15, 442-459. https://doi.org/10.3390/molecules15010442 

Loohuis, L. M., Albersen, M., de Jong, S., Wu, T., Luykx, J. J., Jans, J. J. M., Verhoeven-Duif, N. M., & Ophoff, R. A. (2018). The Alkaline Phosphatase (ALPL) Locus Is Associated with B6 Vitamer Levels in CSF and Plasma. Genes, 10(1), 8. https://doi.org/10.3390/genes10010008 

Tanaka, T., Scheet, P., Giusti, B., Bandinelli, S., Piras, M. G., Usala, G., Lai, S., Mulas, A., Corsi, A. M., Vestrini, A., Sofi, F., Gori, A. M., Abbate, R., Guralnik, J., Singleton, A., Abecasis, G. R., Schlessinger, D., Uda, M., & Ferrucci, L. (2009). Genome-wide association study of vitamin B6, vitamin B12, folate, and homocysteine blood concentrations. American journal of human genetics, 84(4), 477–482. https://doi.org/10.1016/j.ajhg.2009.02.011