Vitamin B6
Compiled from published pharmacological and botanical literature. Not independently verified by Herbuno. Spotted an error or have a correction? Flag it below →
| Compound | Vitamin B6 — pyridoxine, pyridoxal, pyridoxamine and their 5′-phosphates |
|---|---|
| Chemical class | Pyridine derivatives; pyridoxal-5′-phosphate (P5P) is the active coenzyme form |
| CAS | 58-56-0 (pyridoxine HCl) · 853645-22-4 (P5P monohydrate) |
| Primary source | Guava and mango (Psidium guajava, Mangifera indica) for botanical grades; synthesis for isolated grades |
| Key applications | Amino acid transamination, neurotransmitter synthesis, haem synthesis, homocysteine metabolism |
| Claim strength | High for deficiency correction and the neuropathy risk at high dose; Moderate for premenstrual symptoms |
| Typical form | Botanical concentrate at declared assay, pyridoxine HCl, or P5P |
| Buy from Herbuno | Vitamin B6 from Guava / Mango · Liposomal Vitamin B6 (Pyridoxine HCl) · Pyridoxal-5-Phosphate (P5P) |
| Origin | Processed / Sourced from India |
| MOQ | R&D 100 g / 250 g (subject to stock) · Pilot batch 1–5 kg · Bulk 10 kg, 25 kg and above |
| Lead Time | Dispatch within 72 hrs from stock · fresh-batch production (typically 50 kg+): 10 working days |
| Documentation | CoA & MSDS standard with every lot; phytosanitary on request |
Name origin: Pyridoxine is named for its pyridine ring plus the hydroxyl and oxygen functions — pyrid-ox-ine. Vitamin B6 is in fact six related compounds: pyridoxine, pyridoxal and pyridoxamine, each with a 5′-phosphate form. All converge on pyridoxal-5′-phosphate, the coenzyme that actually does the work, which is why the vitamin is defined functionally rather than as a single molecule.
Discovery and production history: B6 was isolated in 1938 by several groups almost simultaneously, following work on a rat dermatitis that was distinct from the pellagra lesion. Its coenzyme role was mapped through the 1940s and 1950s as the dependency of transaminases on P5P became clear. Industrial pyridoxine production has been synthetic from the outset. The modern clinical interest came later and from an unexpected direction: in 1983 Herbert Schaumburg described sensory neuropathy in people taking multi-gram daily doses of pyridoxine, establishing that a water-soluble vitamin could cause serious nerve injury.
Research trajectory: Three threads run through the literature. Deficiency correction is straightforward and uncontested. Pharmacological use in specific conditions — pregnancy nausea, premenstrual symptoms, isoniazid-induced neuropathy, certain inherited seizure disorders — has variable but real support. And the toxicity work has grown steadily, to the point where B6 is now the only B vitamin with a firm tolerable upper intake level, and several European regulators have restricted permitted supplement doses specifically because of it.
Commercial source: Isolated B6 is supplied as pyridoxine hydrochloride, the cheapest and most stable form, or as P5P, the phosphorylated coenzyme. Botanical B6 is extracted from fruit material that accumulates it — guava and mango in our case — and standardised to a declared assay. Because nutritional B6 doses are in single-digit milligrams, botanical grades are comfortably formulable, which is not true of every botanical micronutrient.
Evidence for Vitamin B6 Applications
B6 is the only B vitamin with a well-established toxicity syndrome, and it defines responsible formulation in this category. Chronic high-dose pyridoxine causes a sensory peripheral neuropathy presenting as numbness, tingling and impaired proprioception, sometimes severe enough to affect gait. It was first documented at multi-gram doses but has since been reported at much lower intakes taken over long periods, with some case series implicating doses in the tens of milligrams sustained for months or years. Recovery on withdrawal is usual but not always complete. The EU tolerable upper intake level is 12 milligrams daily and the US level is 100 milligrams; several national regulators have gone further and capped permitted supplement doses. Claim strength: High.
Deficiency correction is reliable and the at-risk groups are specific. B6 deficiency causes a seborrhoeic dermatitis, glossitis, cheilosis, confusion and, in severe cases, seizures, reflecting P5P's role in neurotransmitter synthesis. True dietary deficiency is uncommon in varied diets, but drug-induced deficiency is not: isoniazid, cycloserine, penicillamine and hydralazine all antagonise B6, and co-administration of pyridoxine with isoniazid is standard tuberculosis practice precisely to prevent the neuropathy the drug would otherwise cause — a notable inversion given B6's own neuropathy risk at high dose. Claim strength: High.
P5P versus pyridoxine is sold as settled and is not. The argument for P5P is that it is the active coenzyme requiring no hepatic conversion, which should favour people with impaired conversion. The counter-argument is that P5P cannot cross cell membranes in its phosphorylated state and must be dephosphorylated at the intestinal brush border before absorption and rephosphorylated afterwards — so it does not bypass metabolism, it simply enters at a different point. Head-to-head human data showing clinical superiority at matched doses are limited. P5P is also less stable and considerably more expensive. Claim strength: Moderate.
Pregnancy nausea is one of the better-supported pharmacological uses. Pyridoxine, alone or combined with doxylamine, reduces nausea and vomiting of pregnancy, and the combination is an approved first-line treatment in several jurisdictions with a long safety record. Premenstrual symptom relief has weaker support — meta-analyses suggest a benefit, particularly for premenstrual depression, but trial quality is uneven and doses used in trials sometimes exceed what regulators now permit, which complicates translating the evidence into a legal product. Claim strength: Moderate.
Homocysteine lowering follows the same pattern seen with B12 and folate: the biomarker moves and the outcomes do not. B6 participates in the transsulphuration pathway that clears homocysteine, and supplementation lowers it modestly, more so after a methionine load than fasting. Large trials testing whether that lowering reduces cardiovascular events have been null. The mechanism is real; the clinical claim is not supported. Claim strength: Emerging.
Botanical B6 has no comparative bioavailability data against synthetic pyridoxine, in common with the other botanical micronutrients here. Guava and mango are credible clean-label carriers with genuine consumer recognition in Indian and tropical-fruit positioning. One point does favour the botanical route specifically for B6: because the regulatory ceiling is low, a botanical concentrate delivering single-digit milligrams sits comfortably within permitted doses, where it might not for a nutrient needing hundreds of milligrams. Claim strength: Emerging.
Sourcing vitamin B6 from Herbuno. We supply three routes: a botanical concentrate from guava and mango for clean-label work, liposomal pyridoxine HCl, and pyridoxal-5-phosphate for formulators who specifically want the coenzyme form.
Check your target market's permitted dose before fixing the assay — the EU upper intake level is 12 mg daily and some national regulators cap supplement doses below that, which is unusually restrictive for a B vitamin. All lots ship with CoA and MSDS as standard; request a quotation for pilot or bulk volumes.
Dosage & Formulator Specification
Pyridoxine hydrochloride is roughly 82% pyridoxine by weight, so 10 milligrams of the salt delivers about 8.2 milligrams of the vitamin — a distinction that matters when the legal ceiling is 12 milligrams. P5P monohydrate is declared differently again and converts to a lower B6 equivalence per milligram. Adult RDA is 1.3 milligrams rising to 1.7 for men over fifty. Typical supplement doses of 2 to 10 milligrams sit comfortably within limits; 50 and 100 milligram products exist and are legal in some markets but sit close to or above thresholds elsewhere.
The regulatory position is more restrictive than for any other B vitamin and should be confirmed market by market before the formulation is locked. EFSA's tolerable upper intake level for adults is 12 milligrams daily. The US level is 100 milligrams. Several European national authorities have set permitted supplement maxima below the EFSA figure following the neuropathy case reports. A product designed to a US specification may not be placeable in the EU without reformulation, and this is a common and avoidable cause of launch delay.
Form selection has real formulation consequences beyond cost. Pyridoxine HCl is stable to heat and to a broad pH range and tolerates processing well. P5P is markedly less stable, sensitive to light and to moisture, and degrades faster in blends, so products using it need protective packaging and realistic shelf-life claims. B6 is light-sensitive in both forms and should not be formulated into clear packaging without protection. In liquids, pyridoxine is freely soluble and contributes a slightly bitter note at higher inclusion.
For analytical control, specify which vitamer the assay refers to, since pyridoxine HCl, pyridoxine base and P5P are all legitimately called vitamin B6 and give different numbers. Assay by HPLC with fluorescence or UV detection. For botanical grades require source species and plant part on the certificate — guava and mango fruit in our case — along with extraction solvent, residual solvent limits and heavy metals. India-origin botanical material ships with phytosanitary certification on request alongside CoA and MSDS.
Because the legal ceiling is low and the analytical tolerance is not, headroom deserves explicit attention in this category more than in most. A product declaring 10 milligrams against a 12 milligram limit has almost no margin once assay variation and manufacturing overage are applied, and a batch that tests high is a recall question rather than a quality note. Where a formulation is intended for several markets, design to the most restrictive permitted maximum rather than to the RDA, and agree the overage convention with the supplier in writing. For long-term daily products the case for staying well below the ceiling is stronger still, since the neuropathy reports implicate cumulative exposure over months rather than any single dose.
Frequently Asked Questions — Vitamin B6
Is vitamin B6 safe at high doses?
No, and it is the exception among B vitamins. Chronic high-dose pyridoxine causes sensory peripheral neuropathy — numbness, tingling, impaired proprioception, sometimes affecting gait. First described at multi-gram doses, it has since been reported at much lower intakes sustained over months or years. Recovery on withdrawal is usual but not always complete. The EU upper limit is 12 mg daily.
Should I use P5P instead of pyridoxine?
Only if you have a specific reason. P5P is the active coenzyme, but it cannot cross membranes phosphorylated — it is dephosphorylated at the brush border and rephosphorylated after absorption, so it does not bypass metabolism. Head-to-head clinical superiority data at matched doses are limited, and P5P is less stable and more expensive.
What dose can I legally put in an EU product?
Check market by market, because B6 is unusually restricted. EFSA's upper intake level is 12 mg daily and several national regulators have set permitted supplement maxima below that following the neuropathy reports. A product built to a US specification, where the limit is 100 mg, may not be placeable in the EU without reformulation.
Does B6 help premenstrual symptoms?
Meta-analyses suggest a benefit, particularly for premenstrual depression, but trial quality is uneven. There is a practical complication: some trials used doses above what regulators now permit, so the evidence does not translate cleanly into a legal product. Pregnancy nausea has the stronger support, where pyridoxine with doxylamine is approved first-line treatment in several jurisdictions.
Which vitamer should the certificate state?
Specify it explicitly, because pyridoxine HCl, pyridoxine base and P5P are all called vitamin B6 and give different numbers. Pyridoxine HCl is about 82% pyridoxine by weight, so 10 mg of salt is 8.2 mg of vitamin — which matters a great deal when the ceiling is 12 mg.
Why source B6 from India?
Around 80% of raw nutraceutical ingredients originate in China and a second qualified origin is increasingly a continuity requirement. For botanical B6 the specific case is that guava and mango are major Indian crops with established extraction infrastructure, and because the regulatory ceiling is low, a botanical concentrate delivering single-digit milligrams fits permitted doses comfortably.