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

Many brands add calcium and vitamin D, sometimes in amounts higher than in dairy milk. —Brianna Tobritzhofer, Health, 14 Apr. 2026

Light triggers vitamin D production and is a crucial driver of circadian rhythms. —Maria Godoy, NPR, 13 Apr. 2026

Specific populations are particularly vulnerable to vitamin D deficiency. —Amy Brownstein, Verywell Health, 13 Apr. 2026

It’s loaded with omega-3 fatty acids, provides vitamin D (a nutrient many older adults run low on) and contains calcium from the soft, edible bones. —Allison Palmer, Charlotte Observer, 8 Apr. 2026

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