vitamin D

noun

Definition of vitamin D

: 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

How to pronounce vitamin D<sub>2</sub> (audio)

\ : calciferol

b or vitamin D₃ \ -ˈdē-ˈthrē

How to pronounce vitamin D<sub>3</sub> (audio)

\ : cholecalciferol

Examples of vitamin D in a Sentence

Recent Examples on the Web

Other research has questioned claims made by vitamin D, fish oil and omega-3 supplement makers about their ability to ward off chronic conditions like cancer, cardiovascular disease and cognitive decline. — Jamie Ducharme, Time, "These Dietary Supplements Were Linked to Serious Health Problems in Young People," 6 June 2019 Always wear sunscreen, and get your vitamin D from a supplement instead. — Kiera Carter, Marie Claire, "The Everything SPF Guide: What You Need to Know About Sunscreen," 27 May 2019 These include calcium, magnesium, vitamin D, several B vitamins, vitamin A, vitamin K, potassium, iodine, selenium, borate, zinc, manganese, molybdenum, beta-carotene, and iron. — Korin Miller, Allure, "Do You Need to Take a Multivitamin? Here's What Nutritionists Say," 3 May 2018 In the summer, when the sun is directly overhead, vitamin D synthesis can be very efficient. — New York Times, "Do I Get Enough Vitamin D in the Winter?," 16 Feb. 2018 Modern Greeks had levels of vitamin D deficiency that were four times higher than their ancient ancestors, perhaps due to spending more time indoors or changes in clothing, though researchers have yet to find a definitive answer. — Lorraine Boissoneault, Smithsonian, "How Ancient Teeth Reveal The Roots of Humankind," 2 July 2018 People need cholesterol to make hormones, vitamin D and other substances, but trouble arises when the waxy matter builds up inside the walls of arteries, hardening into plaque that restricts the flow of blood and increases the risk of heart disease. — Jo Craven Mcginty, WSJ, "High Cholesterol? It Must Be January," 18 Jan. 2019 An example of an immunoassay would be a vitamin D test or a PSA test, which is the prostate cancer test, essentially. — Recode Staff, Recode, "Full transcript: WSJ investigative journalist John Carreyrou on Recode Decode," 3 June 2018 Many consumers don’t have a problem with eating fish, which gets rave reviews from doctors and nutritionists for being relatively low in fat while loaded with nutrients, including vitamin D and omega-3 fatty acids. — Anne Marie Chaker, WSJ, "Fish: The Final Frontier in Fake Meat," 15 Oct. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'vitamin D.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.