{"ok":true,"entry":{"slug":"vitamin-b6","kind":"supplement","name":"vitamin b6","aliases":["pyridoxine","pyridoxine hydrochloride","pyridoxal 5'-phosphate"],"brands_sg":["GNC"],"class":"vitamin","tags":["general","cognitive"],"use_for":"protein and amino-acid metabolism · 100+ enzyme reactions","use_after":"no timing rule","use_duration":null,"take_with":"water · absorbed from supplements much like food b6","pros":["rda is small — 1.3 mg a day for adults 19–50","in multis, b-complex and stand-alone forms","pyridoxine hcl is the most common form; p5p also sold"],"cons":["neuropathy reported above 100 mg/day taken long term","ul is 100 mg/day · hsa caps supplements at 100 mg/day","high doses: skin lesions, photosensitivity, nausea"],"dose_note":"rda 1.3 mg (19–50), 1.7 mg men / 1.5 mg women 51+; ul 100 mg/day for adults; sensory neuropathy has been reported below 500 mg/day with long-term use and usually stops once the supplement stops; hsa's limit for health supplements is 100 mg/day","dosage":{"ul":100,"unit":"mg","fda_dv":1.7,"rda_ai":1.3,"ul_status":"established","population":"general adult","hsa_max_daily":100},"ul_status":"established","sg_class":null,"cautions":["pregnancy — the sheet says doses could approach the ul; ask your doctor first","nerve symptoms on high doses (sensory neuropathy, loss of movement control) — usually stop once b6 stops; worth a doctor's check","kidney problems, autoimmune conditions, alcohol dependence — low b6 is common; ask your doctor"],"clashes":[{"src":["nih_ods_b6"],"note":"raises b6 loss in urine; the sheet says b6 supplements can offset this","with":"cycloserine"},{"src":["nih_ods_b6"],"note":"speed up b6 breakdown, lowering plp; b6 may also lower phenytoin and phenobarbital levels","with":"antiepileptics (valproic acid, carbamazepine, phenytoin)"},{"src":["nih_ods_b6"],"note":"users often have low plasma plp","with":"theophylline"}],"sources":[{"id":"nih_ods_b6","url":"https://ods.od.nih.gov/factsheets/VitaminB6-HealthProfessional/","label":"NIH ODS — Vitamin B6 (Health Professional), updated June 16, 2023","quote":"19–50 years: Male 1.3 mg, Female 1.3 mg … 51+ years: Male 1.7 mg, Female 1.5 mg … [UL] 19+ years: 100 mg … involved in more than 100 enzyme reactions, mostly concerned with protein metabolism … chronic administration of 1–6 g oral pyridoxine per day for 12–40 months can cause severe and progressive sensory neuropathy … several reports show sensory neuropathy occurring at doses lower than 500 mg/day … the symptoms usually stop if the patient discontinues the pyridoxine supplements … painful, disfiguring dermatological lesions; photosensitivity; and gastrointestinal symptoms, such as nausea and heartburn … Absorption of vitamin B6 from supplements is similar to that from food sources … it quickly eliminates most of the vitamin in the urine … The most common vitamin B6 vitamer in supplements is pyridoxine (in the form of pyridoxine hydrochloride [HCl]), although some supplements contain PLP … Cycloserine increases urinary excretion of pyridoxine. Pyridoxine supplements can help prevent these adverse effects … Valproic acid, carbamazepine, and phenytoin increase the catabolism rate of vitamin B6 vitamers, resulting in low plasma PLP concentrations … Pyridoxine supplementation (200 mg/day for 12–120 days) can reduce serum concentrations of phenytoin and phenobarbital … Patients treated with theophylline often have low plasma PLP concentrations … Before taking a vitamin B6 supplement, pregnant women should consult a physician because doses could approach the UL","accessed":"2026-08-27"},{"id":"hsa_b6_neuropathy","url":"https://www.hsa.gov.sg/announcements/high-dose-vitamin-b6-and-risk-of-peripheral-neuropathy/","label":"HSA Singapore — High-dose vitamin B6 and risk of peripheral neuropathy (announcement, 15 May 2023)","quote":"Peripheral neuropathy has been reported following chronic high-dose (>100mg/day) consumption of vitamin B6 … The maximum allowable daily limit for vitamin B6 in health supplements is 100mg/day based on data from several long-term studies","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 (clause 4.8 + Table 4 Vitamins Limits)","quote":"4.8 HS for use by the general adult population should not contain vitamins and minerals exceeding the stipulated limits stated in Tables 4 and 5 … Table 4: Vitamins Limits … Nutrient … Maximum Daily Limit … Vitamin B6 100mg","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":"Vitamin B6 … 1.7mg … DVs are the recommended amounts of nutrients to consume or not to exceed each day","accessed":"2026-08-27"},{"id":"watsons_sg_gnc_b6","url":"https://www.watsons.com.sg/vitamin-b6-100mg-tablet-100s/p/BP_69038","label":"Watsons Singapore — GNC Vitamin B6 100mg Tablet (retail listing, SGD)","quote":"Vitamin B6 100mg Tablet 60s … Take one tablet daily","accessed":"2026-08-27"}],"brand_certs":null,"updated_at":"2026-08-29T16:16:34.039038+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."}