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

Ask your provider if taking a calcium or vitamin D supplement may be right for you.1 For many people, menopause symptoms, including joint pain, are worse during the transition to menopause and the first five years after your last period. —Wendy Wisner, Health, 20 June 2025

Specifically, this can occur with calcium, vitamin D, iron, B vitamins (especially B1 and B12) and trace minerals including magnesium and zinc. —Jesse Pines, Forbes.com, 16 June 2025

In addition to advancing age and diets low in protein, other risk factors for osteoporosis include low calcium and vitamin D intake, hormone changes, a sedentary lifestyle, and certain health conditions (e.g., rheumatoid arthritis). —Jonathan Purtell, Verywell Health, 13 June 2025

And vitamin D supplementation may be necessary for those in northern climates or with limited sun exposure. —Daryl Austin, USA Today, 7 June 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