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Vitamin A

Supplement vitamin immuneskin & hair
Aka: retinol, retinyl palmitate
Brands seen in Singapore: California Gold Nutrition, NOW Foods, Bluebonnet Nutrition, Solgar, Vitacost
Not medical advice. Check with your doctor or pharmacist before you start, stop or change the timing of anything you take.
How to use
What it’s for
Vision, immune function, skin and mucous membranes
When to take
No timing rule given
Take with
Retinyl esters absorb 70–90% · beta-carotene only 8.7–65%
Pros & cons
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
Sources
  1. 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) · read 2026-08-27
    what it says
    “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”
  2. NIH ODS — Vitamin A and Carotenoids Fact Sheet for Health Professionals (updated March 10, 2025) — Sources of Vitamin A: Dietary supplements · read 2026-08-27
    what it says
    “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%”
  3. 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) · read 2026-08-27
    what it says
    “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”
  4. NIH ODS — Vitamin A and Carotenoids Fact Sheet for Health Professionals (updated March 10, 2025) — Health Risks from Excessive Vitamin A (teratogenicity) · read 2026-08-27
    what it says
    “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)”
  5. 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) · read 2026-08-27
    what it says
    “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”
  6. NIH ODS — Vitamin A and Carotenoids Fact Sheet for Health Professionals (updated March 10, 2025) — Interactions with Medications (Orlistat; Retinoids) · read 2026-08-27
    what it says
    “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”
  7. FDA — Daily Value on the Nutrition and Supplement Facts Labels, Reference Guide: Daily Values for Nutrients (content current as of 03/05/2024) · read 2026-08-27
    what it says
    “DVs are the recommended amounts of nutrients to consume or not to exceed each day … Vitamin A 900mcg RAE”
  8. 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 · read 2026-08-27
    what it says
    “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”
  9. 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 · read 2026-08-27
    what it says
    “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)”
  10. iHerb Singapore — Vitamin A category, default order (SGD pricing) · read 2026-08-27
    what it says
    “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)”
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Updated 2026-08-29. Every line above traces to a numbered source. Kozen-X is not a medical device and does not give medical advice. It lists what published sources have written down — nothing more. A pair not listed is unrecorded, not cleared. Before you start, stop or re-time anything, talk to your doctor or pharmacist.