E101

Riboflavin is a water-soluble vitamin that is essential for the utilization of energy from food. It is found in milk, meat, eggs, nuts, and vegetables ^{(MedlinePlus 2020)}. It is used to correct vitamin B2 deficiency or aryboflavinosis. At high doses it is used to prevent migraine attacks. Riboflavin is also a food coloring (E101).

The riboflavin concentration in human milk depends on dietary intake of this vitamin being higher in well-nourished women ^{(NIH prof 2022, Allen 2012, Sakurai 2005)}; it is also higher in transitional and mature milk than in colostrum. ^{(Ren 2015)}

The recommended daily allowance (RDA) of vitamin B2 for lactating women is 1.6 mg ^{(NIH 2022, Sauberan 2019, Ares 2015, Hall 2010)}. Supplementation is not necessary in healthy, well-nourished women. ^{(Thomas 1980, Nail 1980)}

Up to 50% of the riboflavin in donated milk is destroyed in bottles or nasogastric tubes exposed to daylight or phototherapy, which may contribute to the high incidence of riboflavin deficiency in premature infants receiving donated breast milk without vitamin supplements. ^{(Bates 1985)}

Given its rapid elimination from the body when consumed in excess, no studies have reported significant adverse effects in humans from excessive consumption of riboflavin through food or supplements ^{(Lee 2023)}. No upper limit (UL) of daily tolerability or toxic dose of this vitamin has been established in humans ^{(Sauberan 2019, EFSA 2006)}. It is recognized as generally safe by the FDA. ^{(FDA 2023)}
With an adequate diet it is not necessary to take supplements of this vitamin. 

Various medical societies and expert authors consider the use of this medication safe during breastfeeding. ^{(Hale, Briggs 2015)}

Recommendations for Drugs in the Eleventh WHO Model List of Essential Drugs: compatible with Breastfeeding. ^{(WHO 2002)}. American Academy of Pediatrics: medication usually compatible with breastfeeding.^{(AAP 2001)}