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

The findings carry potential implications for maternal healthcare and public health policy, especially in populations where vitamin D deficiency is common. —Daniella Gray, MSNBC Newsweek, 29 Oct. 2025

Probiotics Researchers are still learning about the connection between vitamin D and gut health. —Stephanie Brown, Verywell Health, 28 Oct. 2025

The popularity of vitamin D supplementation has increased in recent years. —Sherri Gordon, Health, 28 Oct. 2025

For long-haul trips, consider the Southern Hemisphere for a jolt of vitamin D in a rugged, determinedly uncommercial spot, or take a dip in a memorable, albeit temporary, Japanese onsen. —Mark Ellwood, AFAR Media, 20 Oct. 2025

Word History

First Known Use

circa 1921, in the meaning defined above

Rhymes for vitamin D

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

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