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

-ˈdē-ˈtü 

: calciferol

b

or vitamin D₃

-ˈdē-ˈthrē 

: cholecalciferol

Examples of vitamin D in a Sentence

Recent Examples on the Web

Probiotics Researchers are still learning about the connection between vitamin D and gut health. —Stephanie Brown, Verywell Health, 1 June 2026

Calcium and vitamin D supplementation can help prevent bone loss. —Bethany Brookshire, Scientific American, 29 May 2026

Eating vitamin D-rich foods can help improve calcium absorption in the gut and its deposition into bones. —Emmanuella Ogbonna, Health, 29 May 2026

It’s packed with ceramides, hyaluronic acid, and vitamin D to nourish, plump, and deeply hydrate your complexion. —Olivia Cefalu, InStyle, 23 May 2026

Word History

First Known Use

circa 1921, in the meaning defined above

Rhymes for vitamin D

• abc
• absentee
• addressee
• adoptee
• allottee
• amphorae
• amputee
• apc
• apogee
• appointee
• assessee
• assignee

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

: calciferol

b

: cholecalciferol

called also sunshine vitamin