Prevalence and Associated Factors of Excessive Dietary Supplement Use Among Japanese Adults: Cross-Sectional Study.

Our assessment

This study, published in 2026, looked at what factors are linked to people taking more dietary supplements than the manufacturer recommends. Researchers used purchase history data to get a precise estimate of supplement use. The study design was cross-sectional, meaning it captured a snapshot of behavior at one point in time. The full sample size and participant demographics were not provided in the available data. What this means for you: Because this is a single cross-sectional study without a large sample size reported, it provides initial clues but cannot prove cause and effect.

How it works

The researchers were interested in why some people exceed the recommended dose on a supplement label. They used purchase records to track actual consumption rather than relying on people's memory. The key finding is that overconsumption of dietary supplements is a real issue that can lead to excessive intake of certain nutrients, which may pose health risks. What this means for you: It highlights that simply taking more than the label says does not give you extra benefits — and could actually be harmful. Always stick to the serving size on the bottle unless a doctor tells you otherwise.

Safety profile

Data not available. The side effect reports from the FDA data provided were not included in this study's results. No specific adverse event counts or side effects were listed for this supplement usage pattern in the provided data.

Our recommendation

Read the label on your supplement bottle and follow the recommended dose. Do not assume that more is better. If you are taking multiple supplements, check that you are not doubling up on the same nutrients. What this means for you: Using purchase history data, this study suggests that many people may accidentally take too much. To stay safe, treat your supplements like any other product with a dosing instruction — stick to the serving size.