Vitamin A
Supports vision, immunity and growth.
The formula matches the form shown in the 3D model. Other forms of this vitamin can have different formulas.Loading molecular structure…
Retinol · Drag to rotate
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One representative form. Hydrogens omitted; bonds simplified.
PubChem · CID 445354Where you can find it
- Carrots
- Sweet potatoes
- Spinach
- Eggs
- Dairy
What it does in the body
Vitamin A supports vision, immune defences and normal growth. Some plant carotenoids can be converted into vitamin A.
Recommended amounts & upper limit
US reference values for healthy adults aged 19–50, excluding pregnancy and breastfeeding. These are daily dietary intakes, not blood-test ranges or prescribed supplement doses. Other ages and life stages have different needs; see the original source.
- Men · RDA
- 900 mcg RAE/day
- Women · RDA
- 700 mcg RAE/day
- Upper limit · UL
- 3,000 mcg RAE/dayPreformed vitamin A only, from all sources; not food carotenoids.
RAE means retinol activity equivalents.
How to read these levels
RDA means Recommended Dietary Allowance; AI means Adequate Intake, used when an RDA cannot be set. The upper limit (UL) is not a target or an exact toxicity threshold. Going below the RDA on one day does not diagnose deficiency. No established UL does not mean unlimited amounts are safe.
mg = milligrams; mcg = micrograms. 1 mg = 1,000 mcg. IU is vitamin-specific and cannot be converted with one rule for all vitamins.
What happens when the balance changes?
These are possible effects, not a diagnosis or a prediction from one low or high result.
Too little
Deficiency can cause night blindness and eye damage; severe deficiency can lead to blindness and greater infection risk.
Body areas affected
Eyes and immune system.
Too much
Excess preformed vitamin A can cause headache, nausea and coordination problems; chronic excess can affect the liver. During pregnancy it can cause birth defects.
Body areas affected
Liver, nervous system and developing fetal organs.
What about blood-test levels?
Blood-test levels and daily intake use different units and cannot be compared directly. Test methods, reference ranges and clinical context vary. Symptoms alone cannot establish a vitamin deficiency or toxicity; a clinician can decide which tests and treatment are appropriate.
The body connection
The eye uses vitamin A in the process of sensing light.
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