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

For example, calcium and vitamin D are important for bone health. — Jennifer Lefton, Verywell Health, 22 June 2026

High-fiber meals and certain medications can reduce vitamin D absorption, so timing your supplement may help improve effectiveness. — Emmanuella Ogbonna, Health, 22 June 2026

Rossi, who was not involved with the research, said sunscreen causing vitamin D deficiency is a narrative that has been rampant on social media. — Lily Alvino, NBC news, 18 June 2026

This yellow interior contains much of that choline along with vitamin D, says Zumpano. — Kathleen Felton, Time, 9 June 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