You may already know that vitamin C, a nutrient found in lots of fruit and vegetables, can help your bodyabsorb iron.

That’s why the NHS University Hospital Southampton recommends taking any iron supplements you need alongside something like a glass of orange juice. 

But in a recent video shared on TikTok, doctor Karan Rajan revealed there’s another mineral “most people... including a few doctors” have no idea can affect how we absorb iron.

“There is one very important thing you need to know if you’re prescribed iron supplements which can impact your treatment and how you absorb it,” he began the clip. 

Which is?

The doctor explained: “If you consume too much calcium, either in supplement form or in food, this can actually impact iron absorption.” 

If you’re already dealing with low iron stores, he added, “this could lead to a deficiency”. 

“Calcium competes with iron for absorption in your intestines,” Dr Rajan went on to say. 

It also has an impact on how much non-heme (plant-based) iron your body absorbs, he claimed.

“Calcium salts, like calcium carbonate, which is commonly found in heartburn and indigestion remedies, are alkaline, which can hinder iron absorption.” 

If you have been prescribed both iron and calcium supplements, Dr Rajan said, keep taking both, just at different times of the day, “at least a few hours apart”. 

Meanwhile, “if you’re drinking milk, eating yoghurt, or consuming any calcium-rich foods, consider delaying your iron supplement”.

How do I know if calcium is affecting my iron absorption?

“If you’re being treated for iron deficiency anaemia, it’s worth flagging to your doctor, if they’re not already doing it, that you want to regularly check your calcium levels,” the doctor suggested. 

Calcium is incredibly important for maintaining our bone, and even heart, health so you shouldn’t neglect it just because you’re on an iron supplement ― take both, but ideally a while apart. 

Per healthcare providers and researchers at The Mayo Clinic, calcium-rich foods include: 

• Dairy products, such as cheese, milk and yogurt
• Dark green leafy vegetables, such as broccoli and kale
• Fish with edible soft bones, such as sardines and canned salmon
• Calcium-fortified foods and beverages, such as soy products, cereal and fruit juices, and milk substitutes.