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

Herring are packed with nutrients that support the function and health of the heart and brain, such as omega-3s, vitamin D, and B12. —Jillian Kubala, Health, 6 Nov. 2025

Maximize calcium absorption by pairing it with vitamin D, healthy fats, and proper timing, while avoiding absorption blockers such as high-oxalate foods and excessive caffeine. —Trang Tran, Verywell Health, 5 Nov. 2025

Could there be other differences Israeli children experience - weather, sunshine, vitamin D exposure - that could have contributed? —Meg Tirrell, CNN Money, 3 Nov. 2025

According to Kalliokoski, many pregnant women with clear risk factors for vitamin D deficiency are never tested. —Daniella Gray, MSNBC Newsweek, 29 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