How you prepare your food and what you drink with it can also change how much iron you absorb.
To demonstrate this, Prof Sharp carried out some experiments to mimic human digestion.
The tests mimicked the effect of the enzymes involved in digesting food and the chemical reaction that occurs in human gut cells to show how much iron would be absorbed.
Prof Sharp showed that if you drink orange juice with your fortified breakfast cereal you absorb much more iron than when eating the cereal on its own - because orange juice contains vitamin C, which makes it easier to absorb iron from food.
But, disappointingly, if you drink coffee with your morning bowl of cereal, then that will mean you absorb significantly less iron.
Why? Well, according to Prof Sharp, it's because coffee is full of chemicals called polyphenols that are very efficient at binding to the iron and making that iron less soluble.
So, if a fortified cereal is your breakfast of choice, then having a small glass of orange juice or an orange will help increase your iron uptake. You might also want to consider postponing your morning coffee until at least 30 minutes after you've eaten.