Another study compared the impact of ginger and vitamin B6 on reducing episodes of nausea and vomiting in 126 pregnant women. The results showed that taking 75 mg of B6 each day decreased nausea and vomiting symptoms by 31% after four days ( 29).

The end-product of vitamin B 6 catabolism is 4-pyridoxic acid, which makes up about half of the B 6 compounds in urine. 4-Pyridoxic acid is formed by the action of aldehyde oxidase in the liver. Amounts excreted increase within 1–2 weeks with vitamin supplementation and decrease as rapidly after supplementation ceases. [4] [38] Other vitamin forms excreted in the urine include pyridoxal, pyridoxamine and pyridoxine, and their phosphates. When large doses of pyridoxine are given orally, the proportion of these other forms increases. A small amount of vitamin B 6 is also excreted in the feces. This may be a combination of unabsorbed vitamin and what was synthesized by large intestine microbiota. [4] Deficiency [ edit ] Signs and symptoms [ edit ] Following a recommendation of IUPAC-IUB in 1973, [53] vitamin B 6 is the official name for all 2-methyl,3-hydroxy,5-hydroxymethylpyridine derivatives exhibiting the biological activity of pyridoxine. [54] Moreover, pyridoxine alone should not to be used as a synonym of vitamin B 6. Zhang C, Luo J, Yuan C, Ding D (2020). "Vitamin B12, B6, or Folate and Cognitive Function in Community-Dwelling Older Adults: A Systematic Review and Meta-Analysis". J Alzheimers Dis. 77 (2): 781–94. doi: 10.3233/JAD-200534. PMID 32773392. S2CID 221100310. Mei N, Guo X, Ren Z, Kobayashi D, Wada K, Guo L (January 2017). "Review of Ginkgo biloba-induced toxicity, from experimental studies to human case reports". J Environ Sci Health C Environ Carcinog Ecotoxicol Rev. 35 (1): 1–28. doi: 10.1080/10590501.2016.1278298. PMC 6373469. PMID 28055331. Dietary Reference Values for vitamin B6". EFSA Journal. 14 (6): e04485. 2016. doi: 10.2903/j.efsa.2016.4485. ISSN 1831-4732.

Ristilä M, Strid H, Eriksson LA, Strid A, Sävenstrand H (March 2011). "The role of the pyridoxine (vitamin B6) biosynthesis enzyme PDX1 in ultraviolet-B radiation responses in plants". Plant Physiol Biochem. 49 (3): 284–92. doi: 10.1016/j.plaphy.2011.01.003. PMID 21288732. Vitamin B6 may also play a role in decreasing high blood levels of the amino acid homocysteine, which have been linked to depression and other psychiatric issues ( 6, 7). Enzymatic processes utilize PLP as a phosphate-donating cofactor. PLP is restored via a salvage pathway that requires three key enzymes, pyridoxal kinase, pyridoxine 5'-phosphate oxidase, and phosphatases. [6] [8] Inborn errors in the salvage enzymes are known to cause inadequate levels of PLP in the cell, particularly in neuronal cells. The resulting PLP deficiency is known to cause or implicated in several pathologies, most notably infant epileptic seizures. [8] Another study found that taking 75 mg of vitamin B6 daily during pregnancy decreased symptoms of anemia in 56 pregnant women who were unresponsive to treatment with iron ( 20).

Research shows that people with low blood levels of vitamin B6 have almost double the risk of getting heart disease compared to those with higher B6 levels ( 30).Ahmad I, Mirza T, Qadeer K, Nazim U, Vaid FH (September 2013). "Vitamin B6: deficiency diseases and methods of analysis". Pak J Pharm Sci. 26 (5): 1057–69. PMID 24035968. The contradictory results of these studies may be due to the difference in vitamin B6 dose and study length. The group that took B6 and folic acid had lower homocysteine levels and less abnormal heart tests during exercise than the placebo group, putting them at an overall lower risk of heart disease ( 31).

In infants, a deficiency in vitamin B 6 can lead to irritability, abnormally acute hearing, and convulsive seizures. [1] Less severe cases present with metabolic disease associated with insufficient activity of the coenzyme pyridoxal 5’ phosphate (PLP). [1] The most prominent of the lesions is due to impaired tryptophan– niacin conversion. This can be detected based on urinary excretion of xanthurenic acid after an oral tryptophan load. Vitamin B 6 deficiency can also result in impaired transsulfuration of methionine to cysteine. The PLP-dependent transaminases and glycogen phosphorylase provide the vitamin with its role in gluconeogenesis, so deprivation of vitamin B 6 results in impaired glucose tolerance. [1] [15] Diagnosis [ edit ]Kobayashi D (2019). "[Food Poisoning by Ginkgo Seeds through Vitamin B6 Depletion]". Yakugaku Zasshi (in Japanese). 139 (1): 1–6. doi: 10.1248/yakushi.18-00136. PMID 30606915.

However, vitamin B6 deficiency is thought to be rare in most healthy adults, so there is limited research on using B6 to treat anemia. The starting material is either the amino acid alanine, or propionic acid converted into alanine via halogenation and amination. Then, the procedure accomplishes the conversion of the amino acid into pyridoxine through the formation of an oxazole intermediate followed by a Diels–Alder reaction, with the entire process referred to as the "oxazole method". [9] [12] The product used in dietary supplements and food fortification is pyridoxine hydrochloride, the chemically stable hydrochloride salt of pyridoxine. [13] Pyridoxine is converted in the liver into the metabolically active coenzyme form pyridoxal 5'-phosphate. At present, while the industry mainly utilizes the oxazole method, there is research exploring means of using less toxic and dangerous reagents in the process. [14] Fermentative bacterial biosynthesis methods are also being explored, but are not yet scaled up for commercial production. [13] Functions [ edit ] Studies have linked low levels of vitamin B6 with anemia, especially in pregnant women and women of childbearing age ( 20, 21). Since vitamin B6 helps reduce elevated blood levels of homocysteine, getting enough B6 may lower your risk of this disease ( 42).

4. Note when using the drug Magne B6

a b "Tolerable Upper Intake Levels For Vitamins And Minerals" (PDF). European Food Safety Authority. 2006. Archived (PDF) from the original on 19 September 2017. a b c d e f "USDA Food Data Central. Standard Reference, Legacy Foods". USDA Food Data Central. April 2018 . Retrieved 18 August 2021. PLP is involved in many aspects of macronutrient metabolism, neurotransmitter synthesis, histamine synthesis, hemoglobin synthesis and function, and gene expression. PLP generally serves as a coenzyme (cofactor) for many reactions including decarboxylation, transamination, racemization, elimination, replacement, and beta-group interconversion. [2] [3] [15] Amino acid metabolism [ edit ] The classic clinical syndrome for vitamin B 6 deficiency is a seborrhoeic dermatitis-like eruption, atrophic glossitis with ulceration, angular cheilitis, conjunctivitis, intertrigo, abnormal electroencephalograms, microcytic anemia (due to impaired heme synthesis), and neurological symptoms of somnolence, confusion, depression, and neuropathy (due to impaired sphingosine synthesis). [1] Observational studies suggested an inverse correlation between a higher intake of vitamin B 6 and all cancers, with the strongest evidence for gastrointestinal cancers. However, evidence from a review of randomized clinical trials did not support a protective effect. The authors noted that high B 6 intake may be an indicator of higher consumption of other dietary protective micronutrients. [55] A review and two observational trials reporting lung cancer risk reported that serum vitamin B 6 was lower in people with lung cancer compared to people without lung cancer, but did not incorporate any intervention or prevention trials. [56] [57] [58]