Frequently Asked Questions
Common questions about supplement data, the NIH database, and how PlainVitamins works.
Where does PlainVitamins get its data?
All data comes from the NIH Dietary Supplement Label Database (DSLD), maintained by the National Institutes of Health Office of Dietary Supplements. The DSLD contains label information from dietary supplement products marketed in the United States.
Are the supplement amounts shown in PlainVitamins accurate?
Amounts shown are as declared on the product label as recorded in the NIH DSLD. They are not the result of independent laboratory testing. Dietary supplement label declarations may not always reflect exact product content, independent testing organizations like ConsumerLab, USP, and NSF certify products against their label claims.
Does PlainVitamins recommend specific supplements?
No. PlainVitamins does not recommend supplements or provide medical advice. We present factual data from the NIH DSLD, what ingredients are in each product and at what labeled amounts. Whether any supplement is appropriate for you is a question for a healthcare provider.
What is the NIH Dietary Supplement Label Database?
The NIH DSLD is a database maintained by the National Institutes of Health that captures Supplement Facts panel information from dietary supplement products sold in the United States. It is used by researchers, healthcare providers, and consumers to look up supplement ingredient information.
Why does a supplement I know about not appear in PlainVitamins?
PlainVitamins is built from the NIH DSLD, which is comprehensive but not exhaustive. Newer products, discontinued products, or products that were not captured in the DSLD snapshot may not appear. You can always search NIH DSLD directly at dsld.od.nih.gov.
How do I compare products with different serving sizes?
Ingredient amounts in PlainVitamins are shown per serving as declared on the label. To compare two products with different serving sizes, you need to adjust for the serving difference. For example, if Product A has 500mg Vitamin C per 1 capsule and Product B has 1000mg per 2 capsules, they contain the same amount per capsule.
Are dietary supplements evaluated by the FDA?
Unlike prescription drugs, dietary supplements do not require FDA approval before going to market. The FDA does regulate dietary supplements under DSHEA (Dietary Supplement Health and Education Act), but manufacturers are responsible for ensuring safety and label accuracy. This is why independent third-party testing and databases like the DSLD are valuable.
How current is the PlainVitamins database?
We download the NIH DSLD periodically and rebuild our database. Product formulations can change and new products are added to the DSLD over time. For the most current label information, consult the NIH DSLD directly or the product manufacturer.
Every figure on PlainVitamins is rendered directly from the NIH Dietary Supplement Label Database (DSLD), no number is typed in by an editor. This page draws directly on the NIH DSLD, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.