Guide
What supplement ingredients do, and where to read about them
PlainVitamins says what labels contain and how much; it does not say what an ingredient does in the body. That question has a better source: the fact sheets of the NIH Office of Dietary Supplements, each with its references.
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Written with AI tools under the editorial policy. Every figure is read from the label database, not written by the model.
The ingredients labels list most
Counting each product once, by its current label, among the 116,682 products in the database (nutrition-facts rows such as sugar and sodium left out):
| Ingredient | Products | Share of products |
|---|---|---|
| Vitamin C | 19,919 | 17% |
| Calcium | 19,724 | 17% |
| Vitamin B6 | 15,644 | 13% |
| Vitamin D | 15,307 | 13% |
| Magnesium | 15,088 | 13% |
| Vitamin B12 | 14,774 | 13% |
| Zinc | 13,751 | 12% |
| Niacin | 12,779 | 11% |
| Vitamin E | 12,207 | 10% |
| Potassium | 12,166 | 10% |
| Folate | 12,112 | 10% |
| Vitamin A | 11,596 | 10% |
| Pantothenic Acid (Vitamin B5) | 10,343 | 9% |
| Riboflavin | 10,126 | 9% |
| Thiamin | 10,123 | 9% |
Source: NIH Dietary Supplement Label Database, current labels.
Figures: NIH ODS Dietary Supplement Label Database, version 9.4.0, current labels.
Where to read what each does
The ODS fact sheets cover vitamins, minerals and many botanicals and other ingredients, each in a consumer version and a longer health-professional version with references. For each nutrient they give what it does in the body, how much people need by age (the Recommended Dietary Allowance), food sources, what happens with too little or too much, the upper limit, and interactions with medicines. For herbs, the National Center for Complementary and Integrative Health publishes similar summaries.
What an ingredient page here adds
Each PlainVitamins ingredient page shows the market for that ingredient: how many products list it, the amounts they list per serving (with the Daily Value and adult upper limit marked), the forms labels name, the products that list the most, and how amounts have moved by year. Use the fact sheet to understand the ingredient and the ingredient page to see where a product sits.
About claims on labels
Labels may describe how an ingredient affects the body's structure or function, with the FDA disclaimer; they may not claim to treat or prevent a disease. PlainVitamins quotes label statements as the label's own words and makes no claims about effects.
Where next?
- All ingredientsEvery ingredient on the labels, by group.
- Which forms labels useOxide or glycinate, cyanocobalamin or methylcobalamin.
- The %DV and the upper limitThe two reference numbers.