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

Most foods do not have enough vitamin D to meet people’s needs, so supplements can help fill the gap. — Amy Brownstein, Verywell Health, 17 July 2026

Herring are rich in nutrients that support heart and brain function and health, including omega-3s, vitamin D, and vitamin B12. — Jillian Kubala, Health, 16 July 2026

Sunlight triggers vitamin D production in the skin, and even short periods of daily exposure can make a real impact. — Matthew T. Drake, Fortune, 9 July 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