# PlainVitamins

> What is in a dietary supplement, and how much, against every other label: 116,682 products (214,780 labels) from 5,741 brands in the NIH Dietary Supplement Label Database, version 9.4.0.

Each product page sets every amount on its Supplement Facts label against every product that lists the same ingredient (percentiles and rank), the FDA Daily Value (21 CFR 101.9) and the adult Tolerable Upper Intake Level (Institute of Medicine, 2011). Label data, not medical advice.

## Source

- NIH Office of Dietary Supplements, Dietary Supplement Label Database (DSLD), full download version 9.4.0: https://dsld.od.nih.gov/
- Method: https://plainvitamins.com/methodology

## Pages

- Products: https://plainvitamins.com/supplement/<slug> (every label row against the market, the DV and the UL; closest formulas; label versions)
- Ingredients: https://plainvitamins.com/ingredient/<slug> (the amounts products list, forms, products listing the most)
- Forms of a nutrient: https://plainvitamins.com/ingredient/<nutrient>/<form> (for example https://plainvitamins.com/ingredient/magnesium/glycinate)
- Brands: https://plainvitamins.com/brand/<slug>
- Categories, groups, diets, forms, seals: https://plainvitamins.com/categories, https://plainvitamins.com/for, https://plainvitamins.com/diet, https://plainvitamins.com/form, https://plainvitamins.com/seal
- Search and barcode lookup: https://plainvitamins.com/search?q=<words or UPC>

## Analyses (each with a CSV; the first sentence is its finding)

- Supplement labels above the adult upper limit, nutrient by nutrient: https://plainvitamins.com/research/labels-above-the-upper-limit
  8,383 products in the NIH label database list at least one nutrient above the adult upper intake level when taken at the most servings a day their label allows (DSLD version 9.4.0, January 2026).
- How supplement amounts compare with the Daily Value: https://plainvitamins.com/research/the-market-dose-map
  For 11 of the 24 nutrients with an FDA Daily Value, the median supplement lists more than the Daily Value in one serving (DSLD version 9.4.0, January 2026).
- Proprietary blends: how many supplement labels do not disclose their amounts: https://plainvitamins.com/research/proprietary-blends
  34,198 of the 116,682 products in the NIH label database (29%) list at least one ingredient inside a proprietary blend whose own amount is not disclosed, and 2,746 disclose no amount for any ingredient (DSLD version 9.4.0, January 2026).
- Vitamin D amounts on supplement labels, by year: https://plainvitamins.com/research/vitamin-d-amounts-by-year
  The median vitamin D amount per serving on labels entered in 2025 is 25 mcg (1,000 IU), against 10 mcg (400 IU) in 2011 (DSLD version 9.4.0, January 2026).
- Which forms of magnesium, B12, folate and other nutrients supplements use: https://plainvitamins.com/research/forms-in-the-market
  The most-listed forms are magnesium oxide for magnesium (5,110 products), cyanocobalamin for vitamin B12 (7,144 products), methylfolate (5-MTHF) for folate (2,069 products) (DSLD version 9.4.0, January 2026).
- Gummies, tablets, capsules: how amounts differ by physical form: https://plainvitamins.com/research/amounts-by-physical-form
  For 8 of the 10 nutrients compared, the median gummy lists less per serving than the median tablet (DSLD version 9.4.0, January 2026).
- One formula, many brand names: identical supplement labels: https://plainvitamins.com/research/one-formula-many-brands
  2,044 formulas of four or more ingredients appear, ingredient for ingredient and amount for amount, under two or more brand names, covering 6,154 products (DSLD version 9.4.0, January 2026).
- Third-party seals on supplement labels: how many carry which: https://plainvitamins.com/research/seals-on-supplement-labels
  9,172 of the 116,682 products in the NIH label database (8%) print at least one of nine certification seals on their label (DSLD version 9.4.0, January 2026).
- Prenatal vitamins against the pregnancy Daily Values: https://plainvitamins.com/research/prenatal-labels-and-pregnancy-daily-values
  Of 427 prenatal products, 98% list folate, the nutrient most often present (DSLD version 9.4.0, January 2026).
- The NIH supplement label database in numbers: https://plainvitamins.com/research/the-supplement-label-database-in-numbers
  The NIH Dietary Supplement Label Database holds 214,780 labels for 116,682 products from 5,741 brands; 92,070 of the products (121,959 labels) were on the market at its January 2026 release (DSLD version 9.4.0).

## Guides

- How to read a Supplement Facts label: https://plainvitamins.com/guides/how-to-read-supplement-labels
- The %DV and the upper limit: what the two numbers mean: https://plainvitamins.com/guides/understanding-supplement-labels
- Comparing two supplements with data: https://plainvitamins.com/guides/comparing-supplements-with-data
- Comparing supplement brands by their labels: https://plainvitamins.com/guides/how-to-compare-supplement-brands
- Supplement safety basics, from the label: https://plainvitamins.com/guides/supplement-safety-basics
- What supplement ingredients do, and where to read about them: https://plainvitamins.com/guides/what-supplement-ingredients-actually-do
- What supplement labels contain, in numbers: https://plainvitamins.com/guides/are-supplements-worth-taking

## Tools

- Dose checker: https://plainvitamins.com/tools/dose-checker
- IU to mcg converter: https://plainvitamins.com/tools/iu-converter
- Barcode lookup: https://plainvitamins.com/tools/upc-lookup
- Compare two products: https://plainvitamins.com/compare

More: https://plainvitamins.com/llms-full.txt

## Findings

### Supplement labels above the adult upper limit, nutrient by nutrient
https://plainvitamins.com/research/labels-above-the-upper-limit

8,383 products in the NIH label database list at least one nutrient above the adult upper intake level when taken at the most servings a day their label allows (DSLD version 9.4.0, January 2026). Niacin leads: 35% of the 12,334 products giving its amount pass the 35 mg limit.

Method: For each nutrient with an adult Tolerable Upper Intake Level (UL) that applies to supplements, every product's current label amount is multiplied by the largest number of servings a day its directions state (one serving when the label gives none) and divided by the UL. A product counts as above the limit when that ratio exceeds 1. Products listing the nutrient without an amount are left out of the shares, and so are amounts that are not plausible as printed: outside the range of 99.6% of labels for that nutrient, over 50 times its UL, or more than five times off the label's own printed %DV against both the current Daily Value and the one before the 2016 revision (a unit or transcription slip; labels printed before the change give %DV against the old values), or above the 99th percentile with neither a printed %DV nor the strength in the product's name to back it (the methodology states the rule).

Limits: Three ULs cannot be set against label amounts and are left out: vitamin A (the UL counts preformed retinol only, while labels state vitamin A in mcg RAE or IU, adding beta-carotene), vitamin E (the UL counts supplemental alpha-tocopherol, while most labels state IU, whose weight depends on the natural or synthetic form) and folic acid (the UL counts synthetic folic acid, while labels state folate in mcg DFE across forms). Shares count products giving a plausible amount, so they can differ slightly from the counts on ingredient pages, which include every printed amount. The UL is for healthy adults; children's limits are lower and are not applied here. Some ULs cover only part of the intake (niacin and folic acid count synthetic forms, magnesium counts supplements only), so a label above the UL is not a statement about anyone's total intake. Directions vary; one serving is assumed when the label states none. This is a reading of labels, not medical advice.

### How supplement amounts compare with the Daily Value
https://plainvitamins.com/research/the-market-dose-map

For 11 of the 24 nutrients with an FDA Daily Value, the median supplement lists more than the Daily Value in one serving (DSLD version 9.4.0, January 2026). Vitamin B12 sits highest: the median product lists 36 mcg, 14.6 times the 2.4 mcg Daily Value, and 66% of products list five times the DV or more.

Method: For each nutrient, every current label that gives its amount in the same measure as the FDA Daily Value (21 CFR 101.9(c)(8)(iv), adults and children 4 years and older) is taken at one serving. The median, the middle half and the shares above one and five times the DV are computed over those products.

Limits: Amounts are per serving as printed; directions may call for more or fewer servings. Products giving the nutrient in another measure (for example vitamin A in IU) are left out of that nutrient's figures. The Daily Value is a labelling reference, not a recommendation for any person.

### Proprietary blends: how many supplement labels do not disclose their amounts
https://plainvitamins.com/research/proprietary-blends

34,198 of the 116,682 products in the NIH label database (29%) list at least one ingredient inside a proprietary blend whose own amount is not disclosed, and 2,746 disclose no amount for any ingredient (DSLD version 9.4.0, January 2026). By DSLD product type, blends are most common in "Other Combinations": 46% of those products.

Method: A label row counts as undisclosed when DSLD records it without a quantity inside a blend (the label gives only the blend's total). Products are counted once, by their current label; the brand table covers brands with 100 products or more.

Limits: FDA rules allow a blend to give only its total weight, with ingredients in descending order; an undisclosed amount is lawful and says nothing about quality. DSLD transcribes labels; a transcription that omits an amount the label prints would count here. Published counts from the same database (for example Saldanha and others, "Perspectives on the Use of Proprietary Blends in Dietary Supplements", Journal of Nutrition, 2023, doi:10.1016/j.tjnut.2023.03.035) count labels rather than products and read other releases, so their shares differ from this one.

### Vitamin D amounts on supplement labels, by year
https://plainvitamins.com/research/vitamin-d-amounts-by-year

The median vitamin D amount per serving on labels entered in 2025 is 25 mcg (1,000 IU), against 10 mcg (400 IU) in 2011 (DSLD version 9.4.0, January 2026). The share of products listing 50 mcg (2,000 IU) or more went from 7% to 29%.

Method: Products are grouped by the year their current label entered DSLD. Amounts in IU are converted at 40 IU per mcg (Institute of Medicine, 2011). Years with fewer than 30 products giving a vitamin D amount are left out.

Limits: Entry year is when DSLD recorded the label, not when the product launched; DSLD began in 2011 and its coverage has grown. Per serving as printed; the share above the UL uses the most servings a day the label allows.

### Which forms of magnesium, B12, folate and other nutrients supplements use
https://plainvitamins.com/research/forms-in-the-market

The most-listed forms are magnesium oxide for magnesium (5,110 products), cyanocobalamin for vitamin B12 (7,144 products), methylfolate (5-MTHF) for folate (2,069 products) (DSLD version 9.4.0, January 2026). Across 12 nutrients, this page counts the products naming each form and the median amount they list.

Method: A product counts for a form when DSLD records that compound as the form of the nutrient on its current label (for example magnesium as magnesium glycinate). A product naming two forms counts for both. Medians are of the nutrient amount per serving among products giving it.

Limits: Many labels name no form; they are in the nutrient total but not in any form row. The form says nothing here about absorption or effect; the ODS fact sheets discuss that.

### Gummies, tablets, capsules: how amounts differ by physical form
https://plainvitamins.com/research/amounts-by-physical-form

For 8 of the 10 nutrients compared, the median gummy lists less per serving than the median tablet (DSLD version 9.4.0, January 2026). Vitamin C: 45 mg in a gummy serving against 120 mg in a tablet serving.

Method: Products are grouped by the physical form DSLD records for their current label. For each nutrient and form, the median amount per serving is taken over products that give the amount; cells with fewer than 20 products are left blank.

Limits: A serving may be one or several units (two gummies, for example); amounts are per serving as printed, not per unit. Form says nothing here about absorption.

### One formula, many brand names: identical supplement labels
https://plainvitamins.com/research/one-formula-many-brands

2,044 formulas of four or more ingredients appear, ingredient for ingredient and amount for amount, under two or more brand names, covering 6,154 products (DSLD version 9.4.0, January 2026). The most repeated is sold under 45 brand names across 82 products, among them Apple Cider Vinegar Gummies Apple Flavor (Purely Optimal).

Method: For every product whose current label gives an amount for each of four or more ingredients, the ingredient list with its amounts (rounded to four significant figures, in a common measure) forms a signature. Signatures shared by products of two or more brands are counted.

Limits: Identical label amounts do not prove a common manufacturer, and different labels can come from one maker. Labels with any undisclosed amount are left out, so blends are not compared.

### Third-party seals on supplement labels: how many carry which
https://plainvitamins.com/research/seals-on-supplement-labels

9,172 of the 116,682 products in the NIH label database (8%) print at least one of nine certification seals on their label (DSLD version 9.4.0, January 2026). The USDA Organic seal is the most common, on 3,900 products; contents and manufacturing seals (USP Verified, NSF) appear on 1,779, and sport-testing seals on 1,333.

Method: A product counts for a seal when its current label's seals and symbols statement, as DSLD transcribes it, names that seal. Products are counted once per seal.

Limits: A seal on a label is the label's claim; DSLD does not verify certifications and neither does this site. Each certifier keeps its own searchable list, linked from the seal pages. Seals printed on the carton but not transcribed are missed.

### Prenatal vitamins against the pregnancy Daily Values
https://plainvitamins.com/research/prenatal-labels-and-pregnancy-daily-values

Of 427 prenatal products, 98% list folate, the nutrient most often present (DSLD version 9.4.0, January 2026). Among nutrients most prenatals list, the pregnancy Daily Value reached least often is calcium: under 1% of products giving its amount reach 1,300 mg in one serving.

Method: Prenatal products are those whose name says prenatal (or pre-natal), one per product by its current label. For each nutrient with a pregnancy Daily Value (21 CFR 101.9(c)(8)(iv), pregnant and lactating women), the share listing it and the share reaching the DV in one serving are computed.

Limits: Products sometimes split a day's amount over several servings; one serving is the comparison here. The Daily Value is a labelling reference; a clinician sets what one person needs. This is a reading of labels, not medical advice.

### The NIH supplement label database in numbers
https://plainvitamins.com/research/the-supplement-label-database-in-numbers

The NIH Dietary Supplement Label Database holds 214,780 labels for 116,682 products from 5,741 brands; 92,070 of the products (121,959 labels) were on the market at its January 2026 release (DSLD version 9.4.0). 2020 was the year the most labels entered it (23,435), and the typical product lists 5 rows on its Supplement Facts panel.

Method: Counts of DSLD labels by entry year and off-market year; products are labels grouped by name and brand (letter case and punctuation folded); brands are grouped the same way.

Limits: DSLD aims to cover labels sold in the United States but is not a complete register of products; coverage has grown since 2011. Off-market dates are those DSLD records.