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

Studies have shown that vitamin D supplements can help to improve bone health, brain health and immune function, among other benefits. DHEA (dehydroepiandrosterone), a hormone produced in the adrenal gland, is another of his top picks. —Melissa Rudy, Fox News, 20 Nov. 2024

Statin medications may lower vitamin D levels, and supplementing with vitamin D may negatively impact the medication’s effects. —Amy Brownstein, Ms, Rdn, Verywell Health, 31 Oct. 2024

Keeping your vitamin D levels healthy is also important. —Lauryn Higgins, Flow Space, 30 Oct. 2024

Some people also take supplements like elderberry, vitamin C, vitamin D, or zinc to boost their immunity and help prevent illness.1112 While the cold and flu share many preventative measures, only the flu has a vaccine for treatment and prevention. —Brandi Jones, Msn-Ed, Health, 30 Oct. 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