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

Avocado Avocados are another healthy fat source that can help your body absorb vitamin D better. —Kirstyn Hill, Health, 16 Mar. 2026

The study also showed no difference between the vitamin D and placebo groups in the likelihood that household contacts would contract the virus. —Kelly McGreal, FOXNews.com, 15 Mar. 2026

Other problematic human medications include vitamin D supplements, estrogen creams, antidepressants and other prescription drugs, and recreational drugs including cannabis and amphetamines. —The Washington Post, San Diego Union-Tribune, 14 Mar. 2026

Key Takeaways About 14% of people developed a vitamin D deficiency after one year of taking a GLP-1 medication. —Stephanie Brown, Verywell Health, 12 Mar. 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