Vitamin B6 forms for supplement manufacturing

How the vitamin B6 forms compare

This guide covers two vitamin B6 forms: pyridoxine hydrochloride and pyridoxal 5’-phosphate (P5P) monohydrate. No single form is best for every product. Pyridoxine hydrochloride is the established, lower-cost form, and P5P is chosen when a brand positions a product on the phosphorylated coenzyme form. On an equimolar basis, 1.289 mg of P5P monohydrate carries the same amount of vitamin B6 as 1 mg of pyridoxine hydrochloride.

The ratio comes from the molar masses: 265.16 g/mol for P5P monohydrate and 205.64 g/mol for pyridoxine hydrochloride. Each molecule carries one vitamin B6 unit, so the conversion is a direct molar-mass ratio. The reverse factor is 0.776: 1 mg of P5P monohydrate matches 0.776 mg of pyridoxine hydrochloride.

Vitamin B6 claims are usually in the milligram range, so the 29 % extra mass of P5P rarely affects capsule fill or tablet size. The practical differences lie elsewhere: chemical reactivity, colour, assay basis and cost.

Pyridoxine hydrochloride is a hydrochloride salt of an alcohol form. It is white and dissolves readily in water, which suits effervescent tablets, drink powders and gummies. P5P is a phosphate ester that carries an aldehyde group. Aldehydes react with primary amines to form Schiff bases, so P5P needs care next to amino acids and other amine-containing actives. Its pale yellowish colour can also show in white tablets or clear capsules. Both forms are light-sensitive, so opaque capsules, coated tablets and light-protective packaging are standard practice.

Choosing a form

• Label claim and assay basis. Fix in the specification whether the declared vitamin B6 is expressed as the compound or as a pyridoxine equivalent, and confirm which basis the competent authority of each target market expects. P5P is a monohydrate, and the certificate of analysis states whether its assay is on an anhydrous or as-is basis. Adjust the arithmetic to match, then add overage with the overage calculator.
• Worked example. To deliver the same molar amount of vitamin B6 as 10 mg of pyridoxine hydrochloride, you need 12.9 mg of P5P monohydrate, before assay correction and overage. The elemental content calculator handles the same type of conversion for other nutrients.
• Format. Pyridoxine hydrochloride fits every common format, including effervescent tablets and gummies, where solubility matters. P5P is mostly used in capsules and tablets, where contact with water and reactive ingredients is limited.
• Compatibility. In amino-acid-rich powders and sports nutrition blends, pyridoxine hydrochloride is the simpler choice. If P5P is required, run stability trials on the finished blend and consider separating it from reactive actives.
• Taste and colour. Pyridoxine hydrochloride has a bitter, slightly acidic taste that flavouring must cover in chewables and drinks. P5P adds a faint yellow tint that may need a coloured coating or shell.
• Cost per milligram of vitamin B6. Pyridoxine hydrochloride is the lower-cost route. P5P costs more per milligram of vitamin B6 and needs 29 % more powder for the same molar amount.
• Label wording. Terms such as “active form” may be read as claims. Check them against the health claims guide before artwork is finalised.

SoleChem sends the specification sheet and certificate of analysis with its quote, so the assay basis and storage conditions can be checked before a trial batch. State the grade you need in the quote form.

EU regulatory status

Food supplements in the EU may use only the vitamin forms listed in Annex II of Directive 2002/46/EC. Pyridoxine hydrochloride is listed there as a source of vitamin B6. Pyridoxal 5’-phosphate also appears in the consolidated Annex II. Confirm both entries in the current consolidated text before use. The permitted forms guide explains how Annex II is structured and amended.

Vitamin B6 itself is listed in Annex I of the Directive, which sets the unit used on the label. Labelling of food supplements follows the Directive together with Regulation (EU) No 1169/2011; the vitamin B6 amount is declared under Article 8 of the Directive, because the Regulation’s nutrition declaration section does not apply to food supplements. See the labelling guide for format and wording.

The Directive allows maximum levels to be set at EU level, but harmonised maximum amounts for vitamins in food supplements have not been adopted. Member states set their own limits, and they differ. Some states also have notification procedures for new supplements. The maximum levels guide explains how to find each national rule; the competent authority of each member state publishes the current figures.

If vitamin B6 is added to ordinary foods rather than supplements, Regulation (EC) No 1925/2006 applies, with its own list of permitted forms. Check that list separately for each form, because it is not identical to Annex II of Directive 2002/46/EC.

Authorised health claims for vitamin B6 fall under Regulation (EC) No 1924/2006. The exact permitted wording and conditions of use are in the EU Register of nutrition and health claims.