noun
nutritional supplement; nutrient tonic
Refers to products taken to supplement nutrition, such as tonics, drinks, or pills, often for health maintenance or recovery.
疲れたときに栄養剤を飲む。
I take a nutritional tonic when I'm tired.
サプリメント is a broader term for dietary supplements, often in pill or powder form, while 栄養剤 often implies a liquid tonic or a product with a more medicinal nuance.
Compound of 栄養 (nutrition) and 剤 (medicine, preparation).