{"ok":true,"entry":{"slug":"vitamin-b2","kind":"supplement","name":"vitamin b2","aliases":["riboflavin"],"brands_sg":["NOW Foods","Life Extension","Natural Factors","Nature's Way","Thorne"],"class":"vitamin","tags":["energy","general"],"use_for":"energy production · fat, drug and steroid metabolism","use_after":"no timing rule","use_duration":null,"take_with":"water · absorption tops out at about 27 mg per dose","pros":["rda is small — 1.3 mg men / 1.1 mg women","no ul — 400 mg/day for 3 months without reported harm","no known clinically relevant drug interactions"],"cons":["most people (us data) already get the rda from food","fnb still urges caution with excessive amounts","sg caps b2 in health supplements at 40 mg/day"],"dose_note":"rda 1.3 mg men / 1.1 mg women (19+), 1.4 mg in pregnancy, 1.6 mg lactation; multis commonly give 1.3 mg (100% dv); the body absorbs little from single doses beyond 27 mg and stores only small amounts; no ul, but the fnb says limited adverse-effect data do not mean high intakes are harmless; migraine trials (mostly 400 mg/day) had mixed results and the evidence is rated low quality — 400 mg is 10× singapore's 40 mg/day health-supplement cap; hsa lists higher-dose b2 only for patients with certain genetic or metabolic disorders under professional recommendation","dosage":{"ul":null,"unit":"mg","fda_dv":1.3,"rda_ai":"1.3 mg men · 1.1 mg women","ul_status":"none_established","population":"general adult","hsa_max_daily":40},"ul_status":"none_established","sg_class":null,"cautions":["vegan, or little milk and meat — a listed risk group for low riboflavin; a dietitian or doctor can check","vegetarian athletes — a listed risk group because of higher need; worth a dietitian's check","pregnant or breastfeeding and eating little meat or dairy — listed risk group; ask your doctor","riboflavin transporter deficiency (rare genetic disorder) — high-dose riboflavin is a medical treatment, not a supplement decision"],"clashes":[],"sources":[{"id":"nih_ods_b2_intro","url":"https://ods.od.nih.gov/factsheets/Riboflavin-HealthProfessional/","label":"NIH ODS — Riboflavin (Health Professional), updated May 11, 2022 — Introduction","quote":"Riboflavin (also known as vitamin B2) is one of the B vitamins, which are all water soluble … These coenzymes play major roles in energy production; cellular function, growth, and development; and metabolism of fats, drugs, and steroids","accessed":"2026-08-27"},{"id":"nih_ods_b2_absorb","url":"https://ods.od.nih.gov/factsheets/Riboflavin-HealthProfessional/","label":"NIH ODS — Riboflavin (Health Professional), updated May 11, 2022 — Introduction (absorption)","quote":"The body absorbs little riboflavin from single doses beyond 27 mg and stores only small amounts of riboflavin in the liver, heart, and kidneys … either not absorbed or the small amount that is absorbed is excreted in urine","accessed":"2026-08-27"},{"id":"nih_ods_b2_food","url":"https://ods.od.nih.gov/factsheets/Riboflavin-HealthProfessional/","label":"NIH ODS — Riboflavin (Health Professional), updated May 11, 2022 — Sources: food","quote":"About 95% of riboflavin in the form of FAD or FMN from food is bioavailable up to a maximum of about 27 mg of riboflavin per meal or dose","accessed":"2026-08-27"},{"id":"nih_ods_b2_rda","url":"https://ods.od.nih.gov/factsheets/Riboflavin-HealthProfessional/","label":"NIH ODS — Riboflavin (Health Professional), updated May 11, 2022 — Table 1 RDAs + DV note","quote":"Table 1: Recommended Dietary Allowances (RDAs) for Riboflavin … 19–50 years 1.3 mg 1.1 mg 1.4 mg 1.6 mg … 51+ years 1.3 mg 1.1 mg … The DV for riboflavin is 1.3 mg for adults and children age 4 years and older","accessed":"2026-08-27"},{"id":"nih_ods_b2_supp","url":"https://ods.od.nih.gov/factsheets/Riboflavin-HealthProfessional/","label":"NIH ODS — Riboflavin (Health Professional), updated May 11, 2022 — Dietary supplements","quote":"Multivitamin/mineral supplements with riboflavin commonly provide 1.3 mg riboflavin (100% of the DV) … In most supplements, riboflavin is in the free form, but some supplements have riboflavin 5'-phosphate","accessed":"2026-08-27"},{"id":"nih_ods_b2_status","url":"https://ods.od.nih.gov/factsheets/Riboflavin-HealthProfessional/","label":"NIH ODS — Riboflavin (Health Professional), updated May 11, 2022 — Riboflavin intakes and status","quote":"Most people in the United States consume the recommended amounts of riboflavin … Riboflavin deficiency is extremely rare in the United States","accessed":"2026-08-27"},{"id":"nih_ods_b2_risk","url":"https://ods.od.nih.gov/factsheets/Riboflavin-HealthProfessional/","label":"NIH ODS — Riboflavin (Health Professional), updated May 11, 2022 — Groups at risk (athletes, pregnancy)","quote":"vegetarian athletes are at risk of riboflavin deficiency because of their increased need for this nutrient … Pregnant or lactating women who rarely consume meats or dairy products … are at risk of riboflavin deficiency","accessed":"2026-08-27"},{"id":"nih_ods_b2_risk2","url":"https://ods.od.nih.gov/factsheets/Riboflavin-HealthProfessional/","label":"NIH ODS — Riboflavin (Health Professional), updated May 11, 2022 — Groups at risk (vegans, transporter deficiency)","quote":"Vegans and those who consume little milk in developed countries are also at risk of riboflavin inadequacy … Riboflavin transporter deficiency … is a rare neurological disorder … high-dose riboflavin supplementation can be a life-saving treatment in this population","accessed":"2026-08-27"},{"id":"nih_ods_b2_migraine","url":"https://ods.od.nih.gov/factsheets/Riboflavin-HealthProfessional/","label":"NIH ODS — Riboflavin (Health Professional), updated May 11, 2022 — Riboflavin and health: migraine","quote":"Some, but not all, of the few small studies conducted to date have found evidence of a beneficial effect of riboflavin supplements on migraine headaches … 400 mg/day riboflavin … although the evidence supporting this recommendation is of low quality","accessed":"2026-08-27"},{"id":"nih_ods_b2_ul","url":"https://ods.od.nih.gov/factsheets/Riboflavin-HealthProfessional/","label":"NIH ODS — Riboflavin (Health Professional), updated May 11, 2022 — Health risks from excessive riboflavin","quote":"adverse effects from high riboflavin intakes … (400 mg/day for at least 3 months) have not been reported, the FNB did not establish ULs for riboflavin … the FNB urges people to be cautious about consuming excessive amounts of riboflavin","accessed":"2026-08-27"},{"id":"nih_ods_b2_drugs","url":"https://ods.od.nih.gov/factsheets/Riboflavin-HealthProfessional/","label":"NIH ODS — Riboflavin (Health Professional), updated May 11, 2022 — Interactions with medications","quote":"Riboflavin is not known to have any clinically relevant interactions with medications","accessed":"2026-08-27"},{"id":"hsa_hs_guidelines","url":"https://file.go.gov.sg/hsa-hs-guidelines.pdf","label":"HSA Singapore — Health Supplements Guidelines GL-CHPB-3-001 Rev. No. 020 (January 2026), s4.8 general-adult limits, Table 4 Vitamins Limits + List of Health Claims rows 42, 53 + clause 4.11","quote":"Table 4: Vitamins Limits … Vitamin B2 40mg … Vitamin B2 for patients with certain genetic or metabolic disorders … Help in energy metabolism in the body … Vitamin B2, B3, B5, B6, B12 … Maintain good health … All vitamins and minerals","accessed":"2026-08-27"},{"id":"hsa_prohibited_2025","url":"https://file.go.gov.sg/hsa-chp-prohibited-restricted-ing-guidelines.pdf","label":"HSA Singapore — Guidelines on Prohibited and Restricted Ingredients in Health Supplements and Traditional Medicines, GL-CHPB-1-012 Rev. 001 (October 2025), Annex A row 109","quote":"109. Vitamin B2 Restricted use in HS and TM Maximum Daily Dose … should not provide more than 40mg … Cautionary Statement When for oral use by patients with certain genetic or metabolic disorders","accessed":"2026-08-27"},{"id":"fda_dv","url":"https://www.fda.gov/food/nutrition-facts-label/daily-value-nutrition-and-supplement-facts-labels","label":"FDA — Daily Value on the Nutrition and Supplement Facts Labels (Reference Guide: Daily Values for Nutrients), content current as of 03/05/2024","quote":"Riboflavin 1.3mg … DVs are the recommended amounts of nutrients to consume or not to exceed each day","accessed":"2026-08-27"},{"id":"iherb_sg","url":"https://sg.iherb.com/c/vitamin-b2-riboflavin","label":"iHerb Singapore — Vitamin B2 Riboflavin category page (default order), first listings","quote":"1 - 19 of 19 results … NOW Foods, B-2, 100 mg … Life Extension, Homocysteine Resist … Natural Factors, BioCoenzymated™, B2, Riboflavin 5'-Phosphate, 50 mg … Nature's Way, Riboflavin Vitamin B2, 400 mg … Thorne, Riboflavin 5' Phosphate, 36.5 mg","accessed":"2026-08-27"}],"brand_certs":[{"brand":"Thorne","example":null,"programme":"NSF Certified for Sport","matching_products":0,"brand_total_certified":66}],"updated_at":"2026-08-30T17:59:38.376296+08:00"},"disclaimer":"kozen-x is not a medical device and does not give medical advice. it lists what published sources have written down. absence of a record is not the same as safe."}