Health Reference LibraryHow much vitamin A should I take, and how much is too much?
This entry is part of the Nutri Tailor Health Reference Library — cited research on supplements, nutrients and adjacent areas of health.
Summary
Most people should take none, because dairy, eggs, oily fish and orange and green vegetables cover the 700 microgram reference intake for men and 600 for women, and a single portion of liver supplies more than a week. The NHS ceiling is 1500 micrograms a day of preformed vitamin A from food and supplements together, counted over years rather than days because it stores in the liver and weakens bone at sustained high intakes. Beta carotene from vegetables does not count toward that ceiling. In pregnancy, no supplements containing vitamin A and no liver.
Dose calculator: capsules to reach your vitamin A target
Enter the daily amount of vitamin A you are aiming for and see how many servings of each Nutri Tailor product reach it. Nothing you enter leaves this device. No AI is used.
This tool does arithmetic on the label figures. It is not personal dosing advice and it knows nothing about your history or blood results. The reference intake, the safe upper guide and the trial doses are on this page; talk to your GP or a registered nutritional therapist before changing what you take.
Effective dose
The reference intake is 700 micrograms a day for men and 600 for women. Most people need no supplement at all: dairy, eggs, oily fish and orange and green vegetables cover the reference intake, and a single portion of liver supplies a week or more. A supplement makes sense on a restricted diet or when a GP has found low retinol. Keep the preformed vitamin A total, food plus supplement, under 1500 micrograms a day, and remember that beta carotene from vegetables does not count toward that ceiling.
Safety profile
How much is too much: the NHS says not to have more than 1500 micrograms a day from food and supplements together, and to avoid liver and vitamin A supplements in pregnancy. Vitamin A is fat soluble and stores in the liver, so the harm is cumulative. Regular intakes above 1500 micrograms a day over years weaken bones and raise fracture risk in older adults; very high single doses cause headache, nausea and blurred vision. In pregnancy, high vitamin A harms the baby, so no supplements containing vitamin A and no liver. Anyone eating liver weekly should not take a vitamin A supplement as well.
Guideline positions
NHS vitamins and minerals guidance for vitamin A. NIH Office of Dietary Supplements fact sheet for vitamin A where one exists. The trial doses quoted above are from the sources listed on this page.
Practical framework
Capsules to reach the dose, from the Nutri Tailor range, all made in the UK: [vitamin A oil drops](/products/vitamin-a-oil), 673 micrograms of preformed vitamin A as retinyl palmitate per drop in avocado oil, so one drop covers the reference intake and two drops reach the ceiling; not for use in pregnancy. To read your own result against the UK ranges, use the free blood test result interpreter. This is a summary of published research, not personal health advice. Talk to your GP or a registered nutritional therapist before changing what you take, especially if you are pregnant, have a diagnosed condition or are under ongoing care.
Common misconceptions
That more vitamin A works faster: above the doses the trials used there is no extra effect, only more side effects. That the front of the bottle states the dose: read the per capsule figure and the serving size on the back. That the NHS figure is a toxic threshold: it is the level below which harm is unlikely, which is a different thing.
Sources
- NHS (UK government). Vitamin A (NHS adult guidance). NHS UK (UK government).
- National Institutes of Health Office of Dietary Supplements. NIH Office of Dietary Supplements — Vitamin A Health Professional Fact Sheet. NIH Office of Dietary Supplements (US government).