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

Chen advises women in midlife to aim for 1,000 to 1,200 mg of calcium and 600 to 800 IU of vitamin D daily, ideally from food, with high doses of vitamin D advised for those with low levels. — Cheryl Fenton, Flow Space, 27 Oct. 2026

The examples of vitamin D and synthetic fertilizer already point in this direction. — Literary Hub, 23 Oct. 2026

Research suggests that vitamin D supplements may help reduce inflammation, particularly in people with certain health conditions. — Lindsay Curtis, Verywell Health, 22 Oct. 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