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

There is already a waitlist of more than 500 people for their membership, which will cost $275 per month paid upfront for $500 worth of credits to be used toward sauna and cold plunge, but also IVs and shots of vitamins, hyperbaric oxygen therapy, red light, NAD+, compression and PEMF. —Marisa Meltzer, Vanity Fair, 14 Jan. 2026

At the same time, vitamin D helps suppress excessive immune reactions, protecting against autoimmunity and excessive inflammation. —Maggie O'Neill, Verywell Health, 14 Jan. 2026

Use More Tomato Juice to Boost Vitamin C Tomatoes are a surprisingly rich source of vitamin C. —Jenna Anderson, Health, 14 Jan. 2026

Shapiro says that cabbage is rich in sulfur-containing compounds to help strengthen your immune system’s defences—and vitamin C, which studies have shown can provide antioxidant protection and support immune health. —Audrey Noble, Vogue, 13 Jan. 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 B6
• vitamin B complex
• vitamin C
• vitamin D3
• vitamin E
• vitamin H
• vitamin K3

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