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

In people who are not deficient, vitamin D supplements likely won't relieve OA pain. —Lindsay Curtis, Health, 26 Jan. 2025

And common over-the-counter supplements like vitamin D and calcium can help prevent bone loss associated with menopause. —Tina Reed, Axios, 23 Jan. 2025

This isn’t the first time researchers have shown a relationship between vitamin D and strength. —Alex Hutchinson, Outside Online, 22 Jan. 2025

The task force also noted that supplementation with vitamin D with or without calcium can increase the incidence of kidney stones, though the magnitude of this harm was assessed as small. —Jacqueline Howard, CNN, 17 Dec. 2024

Word History

First Known Use

circa 1921, in the meaning defined above

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