vitamin D

noun

: any or all of several fat-soluble vitamins chemically related to steroids, essential for normal bone and tooth structure, and found especially in fish-liver oils, egg yolk, and milk or produced by activation (as by ultraviolet irradiation) of sterols: such as

Examples of vitamin D in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
A lot of our work now is sitting with elders to pull old knowledge out of memory, and testing traditional foods for vitamin D and other micronutrients. — Liam Freeman, Vogue, 11 Nov. 2026 Deficient calcification sometimes occurs naturally, but biologists suspect vitamin D deficiency when teeth are regularly stratified by layers of hardened and soft dentin. — Andrew Paul, Popular Science, 5 Nov. 2026 Key Takeaways Omega-3 fatty acids, antioxidants, fiber, magnesium, vitamin D, and plant compounds can help regulate inflammation and support overall health. — Lana Barhum, Verywell Health, 4 Nov. 2026 Changes to vitamin D levels could reduce the need for supplements in some babies, especially preterm or at-risk infants. — Sherri Gordon, Parents, 3 Nov. 2026 See All Example Sentences for vitamin D

Word History

First Known Use

circa 1921, in the meaning defined above

Time Traveler
The first known use of vitamin D was circa 1921

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Cite this Entry

“Vitamin D.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/vitamin%20D. Accessed 13 Nov. 2026.

Kids Definition

vitamin D

noun
: any of several vitamins that are needed for normal bone and tooth structure, and are found especially in fish-liver oils, egg yolk, and milk or are produced in response to ultraviolet light

Medical Definition

vitamin D

noun
: any or all of several fat-soluble vitamins chemically related to steroids, essential for normal bone and tooth structure, and found especially in fish-liver oils, egg yolk, and milk or produced by activation (as by ultraviolet irradiation) of sterols: as
b
: cholecalciferol

called also sunshine vitamin

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