-
- To save this word, you'll need to log in.
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
a
or vitamin D2
: calciferol
b
or vitamin D3
: cholecalciferol
Examples of vitamin D in a Sentence
Recent Examples on the Web
What’s more, these fish are also naturally abundant in vitamin D, which helps your body absorb that mineral!
—
Caroline Tien, SELF, 19 Feb. 2025
The sun converts cholesterol in our skin into vitamin D, which provides several benefits.
—
Allison Futterman, Discover Magazine, 13 Feb. 2025
Alongside calcium and vitamin D, protein supports bone density and helps reduce the risk of osteoporosis.
—
Emily Cegielski, Flow Space, 12 Feb. 2025
Choose Foods Rich in Calcium and Vitamin D Individuals taking aromatase inhibitors to treat breast cancer should also increase their intake of calcium and vitamin D since bone loss is a side effect of these medications.
—
Brittany Poulson, Mda, Rdn, Cd, Cdces, Verywell Health, 11 Feb. 2025
See all Example Sentences for vitamin D 
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.
Word History
First Known Use
circa 1921, in the meaning defined above
Dictionary Entries Near vitamin D
Cite this Entry
“Vitamin D.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/vitamin%20D. Accessed 23 Feb. 2025.
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
a
b
: cholecalciferol
called also sunshine vitamin
More from Merriam-Webster on vitamin D
Britannica.com: Encyclopedia article about vitamin D
Love words? Need even more definitions?
Merriam-Webster unabridged
Share