Vitamin K forms for supplement manufacturing

How the forms compare

SoleChem supplies two vitamin K forms for food supplements: phylloquinone (vitamin K1) and menaquinone-7 (MK-7, a vitamin K2). Both are declared on the label as vitamin K in micrograms. The choice therefore turns on physical state, stability, source and regulatory route, not on content per gram.

Label amounts of vitamin K are in micrograms, so neither substance is normally weighed neat into a batch. Manufacturers buy diluted preparations: oil solutions, or powders in which the vitamin is dispersed on or encapsulated in a carrier. The concentration is stated on the specification sheet and certificate of analysis. Mass of preparation per unit equals the label claim divided by that assay.

The label declares mass, not molecules. Because MK-7 has the higher molar mass, 100 µg of MK-7 is about 0.154 µmol, while 100 µg of phylloquinone is about 0.222 µmol. This matters only when comparing the forms on a molar basis, for example in specifications or analytical work.

Physical state differs. Phylloquinone is a viscous oil at room temperature and mixes directly into oil fills. MK-7 is a crystalline solid, so it reaches a softgel dissolved in oil and reaches a tablet as a diluted powder.

Choosing a form of vitamin K

There is no single best form of vitamin K for manufacturing. The right form follows from the product format, the other ingredients and the regulatory position in each target market.

• Format. For softgels and drops, either form works as an oil solution. For tablets and capsules, use a dry diluted preparation chosen so the weighed mass blends uniformly.
• Label claim per unit. Microgram claims need a premix or stepwise dilution to reach content uniformity. Pick the preparation’s concentration with your batch size and blending equipment in mind.
• Co-formulated ingredients. Vitamin K is often combined with vitamin D, such as cholecalciferol, in oil-based products. In tablets it often sits with calcium salts or magnesium salts, which raises the stability point below.
• Stability. Phylloquinone is sensitive to light and alkali. MK-7 in dry blends is known to lose content in contact with alkaline mineral salts such as calcium carbonate and magnesium oxide. Coated or microencapsulated grades are used to separate them, and finished-product stability testing remains necessary. The overage calculator helps size the overage once you have stability data.
• Isomers and source. Both forms exist as geometric isomers, and the all-trans isomer is the one to specify. MK-7 is produced either by fermentation or by chemical synthesis. Ask for the specification to state the all-trans content and the production route.
• Cost per microgram. MK-7 generally costs more per microgram of vitamin K than phylloquinone. Compare offers per microgram of all-trans vitamin K, not per kilogram of preparation.
• Regulatory route. Both forms appear in the EU list of permitted vitamin forms. Vitamin K2 (menaquinone) is also in the Union list of novel foods, with specifications for synthetic and microbiologically produced grades, so check its conditions before choosing a supplier’s grade.

At microgram levels the vitamin adds no noticeable taste. In drops, the carrier oil and any added antioxidant decide the sensory profile. Ask for the carrier, concentration and isomer profile you need in the quote form.

EU regulatory status

Vitamin K is listed in Annex I of Directive 2002/46/EC as a vitamin that may be used in food supplements. Annex II lists the permitted forms of vitamin K as phylloquinone (phytomenadione) and menaquinone. The menaquinone entry was added by amendment, so check its exact wording in the consolidated text before relying on it for MK-7. The permitted forms guide explains how Annex II works.

Novel food status is a separate question from Annex II listing. The Union list of novel foods includes vitamin K2 (menaquinone) produced by a synthetic or microbiological process, with separate specifications for each route. Check the Union list in Implementing Regulation (EU) 2017/2470, made under Regulation (EU) 2015/2283, for the vitamin K2 (menaquinone) entry, the specification that matches the grade offered and its conditions of use. The novel food guide covers the procedure.

Harmonised EU maximum amounts of vitamin K in food supplements have not been set. Member states apply their own maximum levels, and these differ. The maximum levels guide explains where each competent authority publishes its figures.

For labelling, Directive 2002/46/EC requires the amount per daily portion in numerical form, using the unit given in Annex I. For vitamin K that unit is the microgram. The labelling guide covers percentage of reference values under Regulation (EU) No 1169/2011.

Claims about vitamin K are governed by Regulation (EC) No 1924/2006. Take authorised wording only from the EU Register of nutrition and health claims, and see the health claims guide. Use of vitamin K in fortified foods falls under Regulation (EC) No 1925/2006, whose annexes must be checked separately.