VitaminNo.001
Vitamin A
Vision, immune function, skin & cell growth.
Typical / RDA700–900 mcg
Upper limit3,000 mcg‡
EvidenceModerate
How to take it
Timing With a mealFood With fatForm Retinol / beta-carotene
What to know
‡UL is for preformed retinol. Fat-soluble and stored in the liver, so it accumulates and excess is genuinely toxic. Beta-carotene (plant form) is safer — the body converts only what it needs.
Interactions & cautions
- High retinol in pregnancy raises birth-defect risk — avoid high doses.
- Beta-carotene supplements raised lung-cancer risk in smokers — avoid.
Do you actually need it?
Most mixed diets supply enough. Rarely needed as a standalone.
Reference values: NIH Office of Dietary Supplements, adult general population. Educational information only — not medical advice. Confirm with a healthcare professional.