vitamin

noun

vi·​ta·​min ˈvī-tə-mən 

British usually

ˈvi- 

: any of various organic substances that are essential in minute quantities to the nutrition of most animals and some plants, act especially as coenzymes and precursors of coenzymes in the regulation of metabolic processes but do not provide energy or serve as building units, and are present in natural foodstuffs or sometimes produced within the body

Examples of vitamin in a Sentence

This cereal contains essential vitamins and minerals.

Did you remember to take your vitamin?

Recent Examples on the Web

These vegetables are rich in fiber, vitamins, antioxidants and glucosinolates, Goy said. —Andrea Margolis, FOXNews.com, 11 Mar. 2026

Ahead, find the retinal creams and serums that dermatologists consider the (vitamin) A-list of the category; plus, insights on how to properly incorporate them. —Jenny Berg, Vogue, 11 Mar. 2026

The medication, also referred to as folinic acid, is a synthetic form of vitamin B9 that has been used to treat the toxic side effects of chemotherapy. —Annika Kim Constantino, CNBC, 10 Mar. 2026

The assistant can also analyze healthcare purchases made on the website, such as vitamins or blood pressure monitors, in order to ask follow-up questions. —Amina Niasse, USA Today, 10 Mar. 2026

Word History

Etymology

alteration of vitamine, from Latin vita life + English amine

First Known Use

circa 1912, in the meaning defined above

Phrases Containing vitamin

• B vitamin
• vitamin A
• vitamin B
• vitamin B complex
• vitamin C
• vitamin D
• vitamin E
• vitamin H
• vitamin K

Kids Definition

vitamin

noun

vi·​ta·​min ˈvīt-ə-mən 

: any of various substances that are necessary in very small amounts to the nutrition of most animals and some plants, that are important to the control of growth and development by activating and assisting in the function of enzymes, and that are present naturally in many foods or in some cases are produced within the body

Medical Definition

vitamin

noun

vi·​ta·​min ˈvīt-ə-mən, British also ˈvit- 

: any of various organic substances that are essential in minute quantities to the nutrition of most animals and some plants, act especially as coenzymes and precursors of coenzymes in the regulation of metabolic processes but do not provide energy or serve as building units, and are present in natural foodstuffs or are sometimes produced within the body