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

Nutritional supplements with ingredients like biotin, vitamin D, and iron can also support overall hair health—and kickstart hair growth. —Kiana Murden, Vogue, 28 Dec. 2024

Following a balanced diet rich in fiber, antioxidant nutrients, zinc, and vitamin D could help reduce inflammation and manage weight—two factors that can improve HS symptoms. —Merve Ceylan, Health, 26 Dec. 2024

Instead, the Task Force focused on whether vitamin D and calcium supplements prevent falls and fractures in adults who are living independently. —Claire Bugos, Verywell Health, 17 Dec. 2024

Older adults may still need to take vitamin D or calcium for overall health but should take different steps to protect from fractures or reduce the risk of falling. —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