Yes, you can take iron and vitamin C together, and it does no harm. Vitamin C does help your body absorb iron, including the iron in a tablet. But when trials have compared iron taken with and without vitamin C, the extra rise in haemoglobin and ferritin has been small at most. So you do not need to buy vitamin C for your iron, or plan the timing around it.
What the trials found
One trial gave 440 adults with iron-deficiency anaemia their iron tablets either with or without 200mg of vitamin C, and in blood tests over the first eight weeks their haemoglobin and ferritin rose by about the same amount either way. A 2024 review that pooled ten trials found slightly larger rises with vitamin C, but its authors judged the difference probably too small to matter and did not recommend adding it routinely. The absorption effect itself is real: in a study of women with low iron stores, 80mg of vitamin C increased how much iron they absorbed from a single 100mg dose by about 30%. It just has not turned into a meaningfully better blood result.
Where vitamin C matters more
Vitamin C is more useful for the iron in food. Most of the iron in plant foods is in a form the gut takes up poorly, and studies of single meals show that vitamin C in the same meal, for example from a glass of orange juice, can increase how much of it is absorbed. That matters most on a plant-based diet, where the iron in every meal counts.
How to take an iron supplement
Iron is absorbed best on an empty stomach: the NHS advice for ferrous sulfate is to take it 30 minutes before eating, or 2 hours after, and with or after food if it upsets your stomach. If a doctor or pharmacist has suggested taking it with orange juice, there is no harm in carrying on. If iron upsets your stomach, the gentler bisglycinate form is usually easier to tolerate than ferrous sulphate. In trials of women with low iron stores, taking it every other day rather than every day increased how much was absorbed overall, so ask whoever is advising you whether that pattern suits you.
What to keep away from it
Calcium can reduce how much iron you absorb, which is why iron and calcium are best taken apart. Zinc can do the same when the two are taken together on an empty stomach, though not when taken with a meal, and the evidence for magnesium is thin and comes mostly from antacids, so keeping both a couple of hours from your iron is a simple precaution. The NHS advice is to leave a two-hour gap after taking iron before having tea, coffee, eggs or dairy. Some antibiotics need a different gap, because iron can cut how much of the antibiotic you absorb: take ciprofloxacin or doxycycline at least two hours before, or six hours after, any iron supplement. And because iron should not be taken blind, it is worth knowing your ferritin first, which is one of the clearest cases for a blood test before supplementing.
To check iron, vitamin C, or both against any medication you take, the free checker will show you the result and the reasoning.