{"ok":true,"entry":{"slug":"vitamin-b3","kind":"supplement","name":"vitamin b3","aliases":["niacin"],"brands_sg":["California Gold Nutrition","NOW Foods","ProHealth Longevity","Life Extension","Thorne"],"class":"vitamin","tags":["energy","skin-hair"],"use_for":"nad for 400+ enzymes · turning food into cell energy","use_after":"no timing rule","use_duration":null,"take_with":"food, for nicotinic acid — the sheet says it eases flushing","pros":["rda is small — 16 mg ne men / 14 mg ne women","nicotinamide (niacinamide) form does not cause flushing","most people (us data) get more than the rda from food"],"cons":["nicotinic acid 30–50 mg+ typically causes flushing","ul 35 mg/day; 1–3 g/day has caused liver injury","sg caps nicotinic acid at 15 mg, nicotinamide at 450 mg"],"dose_note":"rda 16 mg ne men / 14 mg ne women (19+); ul 35 mg/day for supplemental niacin, both forms, based on flushing; 30–50 mg or more nicotinic acid typically flushes; 1,000–3,000 mg/day nicotinic acid is a drug dose — low blood pressure, glucose problems, gut upset, eye effects and liver injury are listed, more so with extended-release forms; nicotinamide at 3,000 mg/day: nausea, vomiting, liver toxicity; skin claim: hsa allows 'maintenance of normal skin' for b3, and the sheet describes deficiency (pellagra) rash only — no trial data on skin; hsa caps singapore health supplements at 15 mg/day nicotinic acid and 450 mg/day nicotinamide","dosage":{"ul":35,"unit":"mg","fda_dv":"16 mg NE","rda_ai":"16 mg NE men · 14 mg NE women","ul_status":"established","population":"general adult","hsa_max_daily":"15 mg nicotinic acid · 450 mg nicotinamide"},"ul_status":"established","sg_class":null,"cautions":["diabetes or on glucose-lowering drugs — high-dose nicotinic acid can raise blood glucose; ask your doctor first","high-dose nicotinic acid — cardiology bodies advise liver-enzyme, glucose and uric-acid checks before starting; a doctor's job, not a self-check","low blood pressure — pharmacologic doses list hypotension severe enough to raise fall risk","drug-dose niacin (thousands of mg, e.g. for cholesterol) — the sheet says medical approval and supervision only"],"clashes":[{"src":["nih_ods_b3_drugs"],"note":"niacin analogs; interrupt niacin production from tryptophan and its conversion to nad — pellagra can occur","with":"isoniazid, pyrazinamide (tb drugs)"},{"src":["nih_ods_b3_glucose"],"note":"nicotinic acid 1.5 g/day+ can raise blood glucose; glucose monitoring and dose adjustments may be needed","with":"antidiabetes medications"}],"sources":[{"id":"nih_ods_b3_intro","url":"https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/","label":"NIH ODS — Niacin (Health Professional), updated November 18, 2022 — Introduction","quote":"Niacin is the generic name for nicotinic acid (pyridine-3-carboxylic acid), nicotinamide (niacinamide or pyridine-3-carboxamide), and related derivatives … More than 400 enzymes require NAD to catalyze reactions in the body","accessed":"2026-08-27"},{"id":"nih_ods_b3_energy","url":"https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/","label":"NIH ODS — Niacin (Health Professional), updated November 18, 2022 — Introduction (energy)","quote":"NAD is primarily involved in catabolic reactions that transfer the potential energy in carbohydrates, fats, and proteins to adenosine triphosphate (ATP), the cell's primary energy currency","accessed":"2026-08-27"},{"id":"nih_ods_b3_absorb","url":"https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/","label":"NIH ODS — Niacin (Health Professional), updated November 18, 2022 — Introduction (absorption)","quote":"Even when taken in very high doses of 3–4 g, niacin is almost completely absorbed","accessed":"2026-08-27"},{"id":"nih_ods_b3_rda","url":"https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/","label":"NIH ODS — Niacin (Health Professional), updated November 18, 2022 — Table 1 RDAs + DV note","quote":"Table 1: Recommended Dietary Allowances (RDAs) for Niacin … 19+ years 16 mg NE 14 mg NE 18 mg NE 17 mg NE … The DV for niacin is 16 mg for adults and children age 4 years and older","accessed":"2026-08-27"},{"id":"nih_ods_b3_supp","url":"https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/","label":"NIH ODS — Niacin (Health Professional), updated November 18, 2022 — Dietary supplements","quote":"Nicotinic acid and nicotinamide are the two most common forms of niacin in supplements. Some niacin-only supplements contain 500 mg or more per serving … Nicotinamide does not produce skin flushing because of its slightly different chemical structure","accessed":"2026-08-27"},{"id":"nih_ods_b3_status","url":"https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/","label":"NIH ODS — Niacin (Health Professional), updated November 18, 2022 — Niacin intakes and status","quote":"Most people in the United States consume more than the RDA for niacin … 10% of all individuals age 2 and older who took dietary supplements had total niacin intakes that reached or exceeded the UL","accessed":"2026-08-27"},{"id":"nih_ods_b3_deficiency","url":"https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/","label":"NIH ODS — Niacin (Health Professional), updated November 18, 2022 — Niacin deficiency","quote":"Severe niacin deficiency leads to pellagra, a disease characterized by a pigmented rash or brown discoloration on skin exposed to sunlight; the skin also develops a roughened, sunburned-like appearance","accessed":"2026-08-27"},{"id":"nih_ods_b3_cvd","url":"https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/","label":"NIH ODS — Niacin (Health Professional), updated November 18, 2022 — Niacin and health: cardiovascular disease","quote":"Although nicotinic acid is a nutrient, if very high doses (thousands of mg) are taken to treat hyperlipidemias, the supplement is being used as a drug. Such doses should only be taken with medical approval and supervision","accessed":"2026-08-27"},{"id":"nih_ods_b3_flush","url":"https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/","label":"NIH ODS — Niacin (Health Professional), updated November 18, 2022 — Health risks: flushing","quote":"Thirty to 50 mg or more nicotinic acid typically causes flushing … accompanied by burning, tingling, and itching sensations … Supplement users can reduce the flushing effects by taking nicotinic acid supplements with food, slowly increasing the dose over time","accessed":"2026-08-27"},{"id":"nih_ods_b3_liver","url":"https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/","label":"NIH ODS — Niacin (Health Professional), updated November 18, 2022 — Health risks: pharmacologic doses","quote":"pharmacologic doses of 1,000 to 3,000 mg/day, nicotinic acid can also cause more serious adverse effects … hypotension severe enough to increase the risk of falls … High doses of nicotinic acid taken over months or years can also be hepatotoxic","accessed":"2026-08-27"},{"id":"nih_ods_b3_liver2","url":"https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/","label":"NIH ODS — Niacin (Health Professional), updated November 18, 2022 — Health risks: pharmacologic doses (cont.)","quote":"impaired glucose tolerance and insulin resistance; gastrointestinal effects, such as nausea, heartburn, and abdominal pain; and ocular effects, such as blurred or impaired vision … Hepatotoxicity is more likely to occur with the use of extended-release forms of nicotinic acid","accessed":"2026-08-27"},{"id":"nih_ods_b3_monitor","url":"https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/","label":"NIH ODS — Niacin (Health Professional), updated November 18, 2022 — Health risks: monitoring advice (ACC/AHA)","quote":"the American College of Cardiology and the American Heart Association recommend measuring hepatic transaminase, fasting blood glucose or hemoglobin A1C, and uric acid levels in all supplement users before they start therapy","accessed":"2026-08-27"},{"id":"nih_ods_b3_nicotinamide","url":"https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/","label":"NIH ODS — Niacin (Health Professional), updated November 18, 2022 — Health risks: nicotinamide","quote":"Nicotinamide does not cause skin flushing and has fewer adverse effects than nicotinic acid, and these effects typically begin with much higher doses [12]. Nausea, vomiting, and signs of liver toxicity can occur with nicotinamide intakes of 3,000 mg/day","accessed":"2026-08-27"},{"id":"nih_ods_b3_ul","url":"https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/","label":"NIH ODS — Niacin (Health Professional), updated November 18, 2022 — Table 3 ULs","quote":"The FNB has established ULs for niacin that apply only to supplemental niacin … These ULs are based on the levels associated with skin flushing … applies to both forms of supplemental niacin … 19+ years 35 mg","accessed":"2026-08-27"},{"id":"nih_ods_b3_drugs","url":"https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/","label":"NIH ODS — Niacin (Health Professional), updated November 18, 2022 — Interactions: isoniazid, pyrazinamide","quote":"Isoniazid and pyrazinamide … are structural analogs of niacin and interrupt the production of niacin from tryptophan … isoniazid can interfere with niacin's conversion to NAD … pellagra can occur","accessed":"2026-08-27"},{"id":"nih_ods_b3_glucose","url":"https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/","label":"NIH ODS — Niacin (Health Professional), updated November 18, 2022 — Interactions: antidiabetes medications","quote":"Large doses of nicotinic acid can raise blood glucose levels by causing or aggravating insulin resistance … nicotinic acid doses of 1.5 g/day or more are most likely to increase blood glucose levels … might require dose adjustments","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, 100","quote":"Table 4: Vitamins Limits … Nicotinic acid 15mg Nicotinamide 450mg … Help in energy metabolism in the body … Vitamin B2, B3, B5, B6, B12 … Contribute to maintenance of normal skin … Biotin, vitamin A, B2, B3","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 rows 75–76","quote":"75. Nicotinamide Restricted use in HS and TM Maximum Daily Dose … should not provide more than 450mg 76. Nicotinic acid Restricted use in HS and TM Maximum Daily Dose … should not provide more than 15mg","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":"Niacin 16mg NE … mg NE = milligrams of niacin equivalents … 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-b3-niacin","label":"iHerb Singapore — Vitamin B3 Niacin category page (default order), first listings","quote":"1 - 48 of 274 results … California Gold Nutrition, NMN, 175 mg … NOW Foods, Niacinamide, 500 mg … ProHealth Longevity, NMN Pro™ 1000 … Life Extension, Vitamin B3 Niacin, 500 mg … NOW Foods, Niacin, 500 mg … Thorne, ResveraCel®","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."}