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Vitamin C supplement labels in Thailand: what must be shown

10 min read · Updated 9 Nov 2026

Vitamin C supplement labels in Thailand: start with the product category

A vitamin C supplement label in Thailand, whether for tablets, capsules, powder sachets or a multivitamin, follows the rules for food supplements. MOPH Notification No. 293 of 2005 defines a food supplement as a product eaten in addition to normal food, containing nutrients or other substances, in the form of tablets, capsules, powder, flakes, liquid or another form that is not normal food. Most vitamin C products fall inside that definition.

Brand owners usually ask two questions: what must the label show, and how much vitamin C per day is allowed? This article answers both with a focus on the vitamin side: the minimum of 15 percent of the Thai Recommended Daily Intake (Thai RDI), the daily maximum under Notification No. 448, the forms of vitamin C you may use, and the claims you may print.

The general items every supplement label needs, and the full warning rules, are covered in Thai dietary supplement labels. To read and verify the Thai FDA number on a label, see the 13-digit Thai FDA number. Here we summarise only what you need to follow the vitamin rules.

Thai supplement labels: the basic items every product needs

A supplement label first follows the general notification on labelling of prepackaged food, which is now Notification No. 450 of 2024 as amended by No. 474 of 2026, and then adds the supplement-specific items. Basic items include the food name, the food serial number (the Thai FDA number), the name and address of the manufacturer or importer, net quantity, allergen information, the expiry or best-before date, and additive information where additives are used.

No. 474 matters for brands that sell online. It rewrote the labelling exemptions: producers selling directly to consumers, including by e-commerce, are exempt from labels in some cases, but food supplements are one of the groups that are not exempt. Every bottle of vitamin C you sell needs a complete label, even if your brand sells every unit itself.

For labels on products not sold to consumers, such as bulk product sold to another business for repacking, clause 12 as replaced by Notification No. 411 requires Thai, or English for imported products, and at least the food name, food serial number, name and address of the producer or importer, and quantity.

Font sizes, placement and ingredient-specific warnings are covered in the supplement label article linked above. The next section looks only at what the supplement notification adds, and how it affects a vitamin C label.

Supplement-specific items: name, quantity, main ingredients and warnings

Clause 9 of Notification No. 293, as replaced by No. 405, adds these items for food supplements:

• Food name must include the words “food supplement” (in Thai, ผลิตภัณฑ์เสริมอาหาร) as part of the name or next to it, for example food supplement vitamin C.
• Quantity: the number of tablets or capsules per pack; net volume for liquids; net weight for powders and other solids.
• Name and quantity of main ingredients, including any constituent for which a benefit is claimed, in descending order. For a vitamin C product, that means stating vitamin C and how much the product contains; for a multivitamin, every vitamin or mineral that is a main ingredient.

On warnings, Notification No. 411 requires every food supplement to show the word “Warning” in Thai at a font size of at least 1.5 mm inside a rectangular frame, followed by the statements that children and pregnant women should not consume the product and that eating a variety of the five food groups in suitable proportions is advisable. The statement that the product has no effect in preventing or curing diseases must be in bold inside a frame, with contrasting font, frame and label colours. These statements are printed in Thai with the exact wording set by the notification.

If a multivitamin contains another ingredient with its own warning, such as fish oil or certain sweeteners, that warning must be added too; the list is in the supplement label article. Check the mandatory text on your artwork with the label check tool.

How much vitamin C is allowed: 15% of the Thai RDI and a daily maximum

Notification No. 448 of 2023 rewrote clause 5(5) of Notification No. 293 and set two linked rules. First, each vitamin and mineral must not exceed the maximum level per day in its annex. Second, a food supplement whose purpose is to provide vitamins or minerals must contain at least 15 percent of the Thai RDIs set in the nutrition labelling notification.

The Thai RDIs are in Annex 3 of Notification No. 445 of 2023 on nutrition labelling. For vitamin C the value is 100 mg, so 15 percent is 15 mg. The annex to No. 448 sets the vitamin C maximum at 1,000 mg per day. A product sold to provide vitamin C therefore sits within this range:

• Minimum: 15 percent of 100 mg = 15 mg
• Maximum: 1,000 mg per day

Because the maximum is per day, your check must use the directions you will print. If the label recommends several tablets a day, add up the vitamin C from all of them and compare that total with the maximum, not the amount per tablet. Leave a margin for the value your laboratory actually measures, since the product analysis report is part of the evidence filed for the food serial number.

The Thai RDIs in No. 445 are set for the healthy general population over three years of age. They do not cover infants and children under three, pregnant women or patients, so do not use them to make statements aimed at those groups.

No. 448 was published in the Royal Gazette on 4 January 2024 and took effect 180 days after publication. Products authorised under the old criteria before that date may be sold for no more than three years from the effective date. If an existing formula has any vitamin above the new maximum, plan the formula and label change early.

Multivitamins: check every nutrient against its own maximum

The annex to No. 448 lists 26 vitamins and minerals, each with its own daily maximum. A multivitamin must be checked nutrient by nutrient; there is no combined limit. And for every vitamin or mineral the product is meant to provide, the 15 percent minimum applies too.

Units in the annex refer to the vitamin or element itself, such as micrograms RAE for vitamin A, milligrams alpha-TE for vitamin E and micrograms DFE for folate. Convert the amount of the compound you actually add into the same unit before comparing. Do not compare the weight of a salt or compound directly.

Three points deserve extra care from formulation teams:

• Some maximums are below the Thai RDI. Iron has a Thai RDI of 22 mg but a supplement maximum of 15 mg per day. Calcium has a Thai RDI of 1,000 mg but a maximum of 800 mg. Folate has a Thai RDI of 400 µg DFE but a maximum of 330 µg DFE.
• Folate has two values. The annex sets 330 µg DFE for folate and 200 µg for folic acid, so the form you use matters.
• Niacin has two forms. Nicotinamide is capped at 20 mg NE and nicotinic acid at 15 mg NE, while the minimum is 15 percent of the Thai RDI for niacin.

The table in this section collects the values most often used in multivitamins. The rest are in the annex to No. 448 and Annex 3 of No. 445, available in our regulation archive, or you can run your formula through the formula check.

Permitted forms of vitamin C, and when vitamin C is an additive

The Thai FDA issued guidance on the forms of vitamins and minerals that may be used as main ingredients in food, dated 17 November 2025. List No. 1 of that guidance applies to food supplements and names seven forms of vitamin C:

• L-ascorbic acid
• Sodium L-ascorbate
• Calcium L-ascorbate
• Potassium L-ascorbate
• L-ascorbyl 6-palmitate
• Magnesium L-ascorbate
• Zinc L-ascorbate

Forms on this list may be used when applying for a food serial number without first requesting a safety verification or safety assessment. If the vitamin or mineral itself is not on the list, a safety verification is needed. If the vitamin is listed but the form is not, a food safety assessment is needed first. This matters for imported products using an unusual form of vitamin C, so check the list before you order production.

A common source of confusion: L-ascorbic acid also appears in the food additive list of Notification No. 468, as INS 300, with functions such as antioxidant. The difference is purpose. If you add it to give consumers vitamin C, it is a main ingredient and its name and amount must be stated. If you add it to stop rancidity or keep quality in a food, it is a food additive and is declared under the additive rules, because Notification No. 281 does not treat nutrients added for nutritional value as additives. More in food additives and INS numbers.

Vitamin C claims on the label

Notification No. 447 of 2023 on health claims on food labels sorts claims into three kinds: nutrient function claims, other function claims, and disease risk reduction claims. For vitamin C, the kind used most is the nutrient function claim.

The main rules are:

• Only nutrients that have a Thai RDI may carry a nutrient function claim, and the wording must come from List No. 1 of the notification rather than be written freely. The list has 13 statements for vitamin C, such as vitamin C contributes to the protection of cells from oxidative stress, and vitamin C contributes to normal collagen formation for the normal function of cartilage. On a Thai label the claim is printed in the Thai wording of the list.
• The nutrient must be present at the source or high level under the nutrition claim criteria.
• The label must carry nutrition labelling and the statement about eating a variety of the five food groups in suitable proportions.
• The label must not suggest that the product can cure, relieve or prevent disease.
• Claims outside the lists must first be assessed by an agency named by the Thai FDA, then submitted to the Thai FDA for consideration before use.

Statements such as high in vitamin C or source of vitamin C are nutrition claims, with criteria in Annex 4 of Notification No. 445; calculate against those criteria before printing. Advertising outside the label, such as sales posts and videos, follows separate rules; see Thai food advertising rules 2026.

Vitamin C label checklist before printing

Before you send artwork to print or file for a food serial number, run through this list:

• The food name includes the Thai words for food supplement.
• Quantity is shown as the number of tablets or capsules, or net volume or weight.
• The name and amount of vitamin C, and of every other vitamin or mineral that is a main ingredient, are listed in descending order.
• The daily amount under the printed directions is at least 15 mg and at most 1,000 mg of vitamin C.
• For multivitamins, every nutrient is checked against its own maximum, especially iron, calcium and folate.
• The vitamin C form is on List No. 1 of the Thai FDA guidance, or a safety verification or assessment is planned.
• The warning frame and mandatory statements match Notification No. 411.
• Any vitamin C function claim uses the wording in Notification No. 447 and the label has nutrition labelling.
• If you sell online yourself, the label is still complete, because supplements are not exempt under Notification No. 474.

If you want our consultants to check the full formula and label against current rules, reach us through contact, or see our registration service if you are preparing to file.

Sources

1. MOPH Notification No. 293 B.E. 2548 (2005) on food supplements · Open source · Search our archive
2. MOPH Notification No. 405 B.E. 2562 (2019) on food supplements (No. 3) · Open source · Search our archive
3. MOPH Notification No. 411 B.E. 2562 (2019) on food supplements (No. 4) · Open source · Search our archive
4. MOPH Notification No. 448 B.E. 2566 (2023) on food supplements (No. 5) · Open source · Search our archive
5. MOPH Notification No. 445 B.E. 2566 (2023) on nutrition labelling (Thai RDIs in Annex 3) · Open source · Search our archive
6. Thai FDA guidance on permitted forms of vitamins and minerals as main ingredients (17 Nov 2025) · Open source · Search our archive
7. MOPH Notification No. 447 B.E. 2566 (2023) on health claims on food labels · Open source · Search our archive
8. MOPH Notification No. 450 B.E. 2567 (2024) on labelling of prepackaged food · Open source · Search our archive
9. MOPH Notification No. 474 B.E. 2569 (2026) on labelling of prepackaged food (No. 2) · Open source · Search our archive
10. MOPH Notification No. 468 B.E. 2568 (2025) on food additive lists (No. 4) · Open source · Search our archive

This article is for general information. It is not a Thai FDA ruling or legal advice, and rules change — check the latest notification or ask an expert before filing or producing.

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