{"ok":true,"entry":{"slug":"vitamin-a","kind":"supplement","name":"vitamin a","aliases":["retinol","retinyl palmitate"],"brands_sg":["California Gold Nutrition","NOW Foods","Bluebonnet Nutrition","Solgar","Vitacost"],"class":"vitamin","tags":["immune","skin-hair"],"use_for":"vision, immune function, skin and mucous membranes","use_after":"no timing rule given","use_duration":null,"take_with":"retinyl esters absorb 70–90% · beta-carotene only 8.7–65%","pros":["rda 900 mcg rae (men) · 700 mcg rae (women), 19+","retinyl esters from supplements absorb 70–90%","beta-carotene form is not known to cause birth defects"],"cons":["ul 3,000 mcg/day preformed · excess stores in the liver","common stand-alone dose, 3,000 mcg rae, sits at the ul","20 mg/day beta-carotene raised lung cancer in smokers"],"dose_note":"rda 900 mcg rae a day for men and 700 mcg rae for women from 19, 770 mcg rae in pregnancy; the ul is 3,000 mcg a day and applies to preformed vitamin a (retinol, retinyl esters) only — no ul is set for beta-carotene; stand-alone supplements commonly carry 3,000 mcg rae; hsa's limit for general-adult health supplements in singapore is 1.5 mg (5,000 iu) retinol a day","dosage":{"ul":"3,000 mcg/day preformed vitamin A (retinol + retinyl esters); none for beta-carotene","unit":"mcg RAE","fda_dv":"900 mcg RAE","rda_ai":"900 mcg RAE men · 700 mcg RAE women (19+) · 770 mcg RAE pregnancy","ul_status":"established","population":"general adult","hsa_max_daily":"1.5 mg (5,000 IU) retinol"},"ul_status":"established","sg_class":null,"cautions":["pregnant or might be — experts advise against more than 3,000 mcg rae (10,000 iu) a day of preformed vitamin a; birth-defect risk","smokers — 20 mg/day beta-carotene raised lung cancer and death rates in male smokers over 5–8 years (atbc trial)","on oral retinoids (acitretin, bexarotene) — added vitamin a raises hypervitaminosis a risk; ask your doctor first"],"clashes":[{"src":["nih_ods_vita_rx"],"note":"cuts absorption of vitamin a, other fat-soluble vitamins and beta-carotene","with":"orlistat (alli, xenical)"},{"src":["nih_ods_vita_rx"],"note":"raise the risk of hypervitaminosis a when combined with vitamin a supplements","with":"oral retinoids (acitretin, bexarotene)"}],"sources":[{"id":"nih_ods_vita_intro","url":"https://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/","label":"NIH ODS — Vitamin A and Carotenoids Fact Sheet for Health Professionals (updated March 10, 2025) — Introduction + Table 1 RDAs (19–50 years row: male · female · pregnancy)","quote":"Vitamin A is involved in immune function, cellular communication, growth and development, and male and female reproduction … Vitamin A is also critical for vision … 19–50 years 900 mcg RAE 700 mcg RAE 770 mcg RAE","accessed":"2026-08-27"},{"id":"nih_ods_vita_supp","url":"https://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/","label":"NIH ODS — Vitamin A and Carotenoids Fact Sheet for Health Professionals (updated March 10, 2025) — Sources of Vitamin A: Dietary supplements","quote":"Amounts of vitamin A in supplements vary widely, but 3,000 mcg RAE (333% of the DV) is common … The absorption of preformed vitamin A esters from dietary supplements is 70%–90%, and that of beta-carotene ranges from 8.7% to 65%","accessed":"2026-08-27"},{"id":"nih_ods_vita_ul","url":"https://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/","label":"NIH ODS — Vitamin A and Carotenoids Fact Sheet for Health Professionals (updated March 10, 2025) — Health Risks from Excessive Vitamin A + Table 3 ULs for Preformed Vitamin A (19+ years row)","quote":"Because vitamin A is fat soluble, the body stores excess amounts, primarily in the liver … (ULs) for Preformed Vitamin A … 19+ years 3,000 mcg … The FNB has not established ULs for beta-carotene and other provitamin A carotenoids","accessed":"2026-08-27"},{"id":"nih_ods_vita_preg","url":"https://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/","label":"NIH ODS — Vitamin A and Carotenoids Fact Sheet for Health Professionals (updated March 10, 2025) — Health Risks from Excessive Vitamin A (teratogenicity)","quote":"Total intakes of preformed vitamin A that exceed the UL … can cause congenital birth defects … Experts advise women who are or might be pregnant … not to take high doses (more than 3,000 mcg RAE [10,000 IU] daily)","accessed":"2026-08-27"},{"id":"nih_ods_vita_atbc","url":"https://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/","label":"NIH ODS — Vitamin A and Carotenoids Fact Sheet for Health Professionals (updated March 10, 2025) — Health Risks from Excessive Vitamin A (beta-carotene; ATBC trial)","quote":"Unlike preformed vitamin A, beta-carotene is not known to be teratogenic … the ATBC trial found that supplementation with a large amount of beta-carotene (20 mg/day) … for 5–8 years increased the risk of lung cancer and mortality … in male smokers","accessed":"2026-08-27"},{"id":"nih_ods_vita_rx","url":"https://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/","label":"NIH ODS — Vitamin A and Carotenoids Fact Sheet for Health Professionals (updated March 10, 2025) — Interactions with Medications (Orlistat; Retinoids)","quote":"Orlistat (Alli, Xenical) … can decrease the absorption of vitamin A, other fat-soluble vitamins, and beta-carotene … acitretin (Soriatane) and bexarotene (Targretin) … Retinoids can increase the risk of hypervitaminosis A when taken in combination with vitamin A supplements","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":"DVs are the recommended amounts of nutrients to consume or not to exceed each day … Vitamin A 900mcg RAE","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 61 + 102","quote":"Table 4: Vitamins Limits … Vitamin A (retinol) 1.5mg (5000IU) … Provitamin A/vitamin A to help maintain eyesight, skin, membranes and immune function … Maintain healthy skin • Vitamin A","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 107","quote":"107. Vitamin A (retinol) Restricted use in HS and TM Maximum Daily Dose When for oral use by general adult population, the maximum recommended daily dose should not provide more than 1.5mg (5000IU)","accessed":"2026-08-27"},{"id":"iherb_sg","url":"https://sg.iherb.com/c/vitamin-a","label":"iHerb Singapore — Vitamin A category, default order (SGD pricing)","quote":"California Gold Nutrition, Vitamin C Gummies with Vitamin A from 100% Beta-Carotene … NOW Foods, Vitamin A, 3,000 mcg (10,000 IU) … Bluebonnet Nutrition, Vitamin A, 3,000 mcg (10,000 IU) … Solgar, Dry Vitamin A … Vitacost, Vitamin A, 3,000 mcg (10,000 IU)","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."}