Thai FDA's New Guidance on Vitamin and Mineral Forms in Food Supplements

Thailand's Food Division has issued a new guidance that changes how formulators need to think about vitamin and mineral ingredients in food supplements. Dated November 18, 2025, the guidance is titled "Guidance on the Use of Forms of Vitamins and Minerals as Key Components in Food Products," and it addresses a question that Thailand's existing vitamin and mineral framework had left largely unanswered: not how much of a nutrient a supplement may contain, but which specific chemical forms of that nutrient Thai FDA will accept without requiring a separate safety review first.

This is a distinct question from the one DeeMED has already covered on this site regarding MOPH Notification No. 448 and its nutrient tolerance bands. No. 448 governs quantity: the minimum and maximum amount of a given vitamin or mineral a supplement may deliver per serving. The new guidance governs form: whether the specific salt, chelate, or compound used to deliver that nutrient is one Thai FDA already recognizes as safe, or one it has not yet evaluated. A formulation can sit comfortably inside the No. 448 dosage bands and still trigger a new compliance step under this guidance, if the particular chemical form supplying that dose is not one Thai FDA has already reviewed.

What the Guidance Actually Changes

The mechanism at the center of the guidance is straightforward in concept, even though it introduces a new decision point into formulation planning. The guidance is issued with an attached schedule, an annex listing specific vitamin and mineral chemical forms that Thai FDA has already reviewed and accepts for use in food products, supplements included. A formulator using a vitamin or mineral source that appears on that schedule can proceed with product registration without triggering any additional ingredient-specific safety assessment on the form itself; the quantity still has to fit within the applicable No. 448 band, but the form itself is treated as pre-cleared.

The other side of that mechanism is where the guidance has real teeth. Any vitamin or mineral chemical form that does not appear on the schedule automatically triggers a food safety assessment before Thai FDA will accept it as an ingredient in a registered product. This is not a discretionary review that Thai FDA might or might not require depending on the case; the guidance frames it as the default consequence of using an off-list form. A company that formulates around a chemical form outside the schedule should expect to need a completed safety assessment as a precondition of registration, not as an optional extra step it can skip.

This structure mirrors a pattern that shows up elsewhere in Thailand's food regulatory framework, most visibly in the 15-year novel food rule under MOPH No. 376: a positive list of pre-cleared items moves quickly, and anything outside that list requires its own case-by-case safety evaluation before it can proceed. The vitamin and mineral forms guidance applies that same logic to a narrower and more technical question, but the practical effect for a formulator is the same. Being on the list is fast. Being off the list means budgeting time and documentation for an assessment that a competitor using a listed form does not have to go through at all.

Why Chemical Form Matters Separately From Dose

Vitamins and minerals rarely appear in a supplement in their pure elemental state. A mineral like zinc, magnesium, or calcium is delivered through a specific salt or chelate, chosen for reasons that range from bioavailability and stability to cost and manufacturing convenience. The same underlying nutrient can be delivered through several chemically distinct forms, each with its own absorption profile, its own stability characteristics under storage and processing, and in some cases its own history of use in different markets around the world. Regulators that only specify a maximum and minimum amount of "zinc" or "magnesium" in a product, without addressing which specific compounds are acceptable sources of that nutrient, leave open a real gap: a novel or unusual chemical form could deliver the labeled dose while introducing safety questions that a simple quantity limit was never designed to catch.

That is the gap this guidance closes. By publishing a schedule of accepted forms and making everything else default into a safety assessment requirement, Thai FDA is drawing a line around the specific compounds it has already evaluated as safe delivery vehicles for a given nutrient, separate from the question of how much of that nutrient a product may contain. Two products could deliver an identical, fully compliant dose of the same vitamin under No. 448 and land in entirely different compliance postures under this new guidance, depending solely on which chemical form each one uses to get there.

The Practical Risk for Foreign Supplement Brands

This distinction matters most for supplement brands built around markets outside Thailand, where a formula's chemical forms were selected against a different regulator's own accepted-ingredient framework. A vitamin or mineral salt that clears without issue in the United States, the European Union, or elsewhere in ASEAN is not automatically presumed acceptable in Thailand simply because it is legal and common somewhere else. Novel chelates designed to improve absorption, less common organic-acid salts chosen for stability or taste masking, or newer proprietary mineral complexes marketed on bioavailability claims are exactly the kind of ingredient choices most likely to fall outside an existing schedule built around the forms Thai FDA has reviewed to date.

The consequence of landing outside the schedule is not a rejected application with no path forward. It is a documented, defined requirement: complete a food safety assessment on that specific chemical form before the product can be registered. That is a real cost in time, and depending on the form, potentially in supporting data as well, but it is a knowable and plannable cost, provided it is identified before a dossier is submitted rather than discovered afterward. A company that submits a registration application built around an unlisted form without having anticipated the assessment requirement will lose the time this guidance is designed to signal in advance, not because the form is unsafe, but because Thailand has not yet formally evaluated it under this specific pathway.

This is a new item to add to formula screening, not a replacement for the checks already required under Thailand's existing supplement framework. A formula still needs its vitamin and mineral doses checked against the No. 448 maximum and minimum bands, its herbal ingredients checked against Thai FDA's positive plant-ingredient list, and any sufficiently new ingredient checked against the 15-year novel food threshold under No. 376. This guidance adds a fourth, narrower check that applies specifically to the chemical form of any vitamin or mineral ingredient, and it belongs at the same early stage of product development as the others, before a dossier is drafted, not after a submission comes back with a request for additional data.

What Formulators Should Check Before Submission

The clearest lesson from this guidance is that vitamin and mineral sourcing decisions can no longer be made purely on dose, cost, and bioavailability grounds without also confirming the specific compound's status against Thai FDA's accepted-forms schedule. For a brand already selling in Thailand, this means reviewing existing formulas against the schedule to confirm whether any currently used chemical form now falls outside it, since a form used in a product registered before this guidance was published may not have been evaluated against it at all. For a brand preparing to enter the Thai market for the first time, this means building the chemical-form check into ingredient sourcing decisions from the start, rather than finalizing a formula around forms selected for other markets and discovering the gap only once a Thai dossier is underway.

Because the guidance was only published in November 2025, most companies working on Thai supplement registrations have not yet built this check into their standard formulation process. That makes it exactly the kind of gap worth catching now, while a formula is still adjustable, rather than after submission when the only options left are a slower assessment process or a formulation change under time pressure.

DeeMED Consulting reviews vitamin and mineral chemical forms against Thai FDA's current accepted-forms schedule as part of its broader supplement ingredient approval and novel food dossier preparation work, alongside the dose, herbal-ingredient, and novel food checks every formula headed into Thai FDA registration already needs.