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

Taking regular multivitamins could also help replace essential vitamins and minerals lost during alcohol metabolism, Police says. —Lauren J. Young, Scientific American, 17 Mar. 2026

There are treatment rooms for IV vitamin therapy and access to functional medicine doctors, hyperbaric oxygen therapy, skin care, acupuncture, physical therapy, and energy work. —Cindy Krischer Goodman, Sun Sentinel, 16 Mar. 2026

However, corned beef is a good source of protein and offers nutrients like iron and vitamin B12. —Sarah Garone, Health, 16 Mar. 2026

Take the quiz here … HIDDEN BENEFIT — Common vitamin could bring relief from long COVID symptoms, study suggests. —FOXNews.com, 16 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