riboflavin
noun
ri·bo·fla·vin ˌrī-bə-ˈflā-vən 
ˈrī-bə-ˌflā-
: a yellow crystalline compound C17H20N4O6 of the vitamin B complex that occurs both free (as in milk) and combined (as in liver) as a component of coenzymes (such as FMN) which are essential to normal metabolism
called also vitamin B2
Example Sentences
Recent Examples on the Web Sea moss contains a decent amount of riboflavin (B2) and folate (B9). 
Adele Jackson-gibson, Good Housekeeping, 17 Jan. 2020 With the loads of vitamin C from the oranges and the combination of vitamin B6, vitamin C, vitamin D, riboflavin and manganese found in avocados, your immune system will be thanking you. Drake Wilson, Sunset Magazine, 10 Feb. 2020 Truth be told, mushrooms supply several key nutrients including the B vitamins niacin, riboflavin, folate and B6, as well as iron, potassium, and selenium. Darlene Zimmerman, Detroit Free Press, 19 Jan. 2020 The B vitamins in whole grains, including thiamine, niacin and riboflavin, are crucial metabolism aids. Jenna Birch, Washington Post, 19 Aug. 2019 Mushrooms are rich in B vitamins: riboflavin [B2], folate [B9], thiamine [B1], pantothenic acid [B5], and niacin [B3]. Lisa Mulcahy, Good Housekeeping, 3 June 2019 In general, though, much of the grain’s fiber and key vitamins and minerals, like iron and the B vitamins niacin, riboflavin, and thiamin, per the FDA, and sometimes some protein, are removed during processing. Carolyn L. Todd, SELF, 18 May 2019 Manufacturers may also add vitamin B12, calcium, and riboflavin to oat milks to provide some nutrients found naturally in cow’s milk. Jaclyn London, Ms, Rd, Cdn, Good Housekeeping, 11 Apr. 2019 While the amount of fat in your milk may vary, know that all cow’s milk contains the same nine essential nutrients: Calcium, protein, vitamin D, phosphorus, vitamin A, riboflavin, vitamin B-12, magnesium, potassium, and niacin. Kathy R. Byrnes, Cincinnati.com, 3 June 2017 See More
Adele Jackson-gibson, Good Housekeeping, 17 Jan. 2020 With the loads of vitamin C from the oranges and the combination of vitamin B6, vitamin C, vitamin D, riboflavin and manganese found in avocados, your immune system will be thanking you. Drake Wilson, Sunset Magazine, 10 Feb. 2020 Truth be told, mushrooms supply several key nutrients including the B vitamins niacin, riboflavin, folate and B6, as well as iron, potassium, and selenium. Darlene Zimmerman, Detroit Free Press, 19 Jan. 2020 The B vitamins in whole grains, including thiamine, niacin and riboflavin, are crucial metabolism aids. Jenna Birch, Washington Post, 19 Aug. 2019 Mushrooms are rich in B vitamins: riboflavin [B2], folate [B9], thiamine [B1], pantothenic acid [B5], and niacin [B3]. Lisa Mulcahy, Good Housekeeping, 3 June 2019 In general, though, much of the grain’s fiber and key vitamins and minerals, like iron and the B vitamins niacin, riboflavin, and thiamin, per the FDA, and sometimes some protein, are removed during processing. Carolyn L. Todd, SELF, 18 May 2019 Manufacturers may also add vitamin B12, calcium, and riboflavin to oat milks to provide some nutrients found naturally in cow’s milk. Jaclyn London, Ms, Rd, Cdn, Good Housekeeping, 11 Apr. 2019 While the amount of fat in your milk may vary, know that all cow’s milk contains the same nine essential nutrients: Calcium, protein, vitamin D, phosphorus, vitamin A, riboflavin, vitamin B-12, magnesium, potassium, and niacin. Kathy R. Byrnes, Cincinnati.com, 3 June 2017 See More Word History
Etymology
International Scientific Vocabulary ribo- + Latin flavus yellow — more at blue
First Known Use
1935, in the meaning defined above
Medical Definition
riboflavin
noun
ri·bo·fla·vin ˌrī-bə-ˈflā-vən, ˈrī-bə-ˌ
variants also riboflavine
-ˌvēn
: a yellow crystalline compound C17H20N4O6 that is a growth-promoting member of the vitamin B complex and occurs both free (as in milk) and combined (as in liver)
called also lactoflavin, ovoflavin, vitamin B2