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

Rich in calcium and vitamin D, dairy products support bone health. —Alexa Mikhail, Fortune, 15 Apr. 2025

Even essential nutrients like vitamin D and vitamin A can become toxic past a certain level of exposure. —Lauren Leffer, Popular Science, 9 Apr. 2025

Specific vitamins like biotin, iron, zinc, vitamin C, vitamin D, and vitamin B12 are essential for nail growth, adds Dr. Patel, and deficiencies can not only lead to slow-growing nails, but also brittle or ridged ones. —Catharine Malzahn, Glamour, 3 Apr. 2025

Previous research has shown that vitamin D deficiency can increase the risk of multiple sclerosis (MS) — and a new study suggests that supplementing it in high doses could help reduce symptoms. —Melissa Rudy, FOXNews.com, 2 Apr. 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