Dietary supplement and Vitamin pill

Dietary supplement noun - Something added to complete a diet or to make up for a dietary deficiency.

Vitamin pill and dietary supplement are semantically related. In some cases you can replace phrase "Vitamin pill" with "Dietary supplement", this phrases are similar.

Vitamin pill noun - A pill containing one or more vitamins; taken as a dietary supplement.

Dietary supplement and vitamin pill are semantically related. You can use "Dietary supplement" instead a noun phrase "Vitamin pill".