Vitamin A
Vitamin A is a group of fat-soluble compounds, such as retinol from animal foods. Plants supply carotenoids like beta-carotene that the body can convert to it.
Also listed as retinol, retinal, retinoic acid, tretinoin
The upper limit is not a daily goal
EFSA’s adult upper limit is 3,000 µg retinol equivalents of preformed vitamin A daily from all sources; the US limit for adults aged 19 and older is also 3,000 µg. The limit applies to retinol and retinyl esters, not food carotenoids. Children have lower limits, and the amount in multiple supplements and foods must be considered together. 1 2
What can too much do?
Chronic excess can cause dry skin, painful muscles or joints, fatigue and abnormal liver tests. Very large acute doses can cause severe headache, nausea and blurred vision. These risks reflect accumulated or excessive preformed vitamin A, not a reason to avoid ordinary carotenoid-rich vegetables. 2 3
Pregnancy changes the stakes
Too much preformed vitamin A can cause birth defects. EFSA advises people who are pregnant or planning pregnancy not to eat liver, offal or products made from them. A prenatal product and a separate vitamin A supplement need to be assessed together rather than treated as unrelated sources. 1 2
Beta-carotene is not risk-free in a capsule
High-dose beta-carotene supplements increased lung-cancer risk in trials involving smokers and people exposed to asbestos; concern also extends to former smokers. EFSA advises smokers against beta-carotene supplements. These findings concern concentrated supplements, not a warning against carrots or leafy vegetables. 1 2
Which medicines matter?
Orlistat can reduce absorption of vitamin A and other fat-soluble vitamins. Oral retinoids can increase toxicity risk when combined with vitamin A supplements. NIH advises people taking medicines regularly to discuss their vitamin A status with their healthcare provider. 2
For information, not individual medical advice. Ingredient studies do not establish the effectiveness of these products.