Iron is required for the formation of haemoglobin which is a protein in red blood cells that helps transports oxygen around the body. Oxygen is needed in order for all of our organs and tissues to function. This is why we can feel tired if we have low iron levels because we cannot deliver sufficient oxygen around our body. Iron is also important to support the immune system and for energy metabolism.
Iron
In terms of how much iron our body needs, the Reference Nutrient Intake (RNI) for women is 14.8mg per day and 8.7mg per day for men.
There isn`t just one type of iron either; there's haem iron which is found only in animal products - meat (red meat being the richest source), with lower amounts being found fish and poultry. This type is more easily absorbed. The other type is called non-haem iron and is found in plant foods (good news for vegetarians and vegans), and fish, meat and supplements.
Foods containing non-haem iron are:
- dark green leafy veg such as broccoli, spinach, cabbage, kale
- beans and pulses
- nuts
- dried fruits
- eggs
- breakfast cereals and flours fortified with iron
- wholegrains such as brown rice and wholemeal bread
There are some dietary components that can enhance our absorption of iron:
Meat: as well as being haem iron rich itself, eating meat alongside iron rich vegetables can boost the amount of iron we absorb from these vegetables (the haem iron aids non-haem iron absorption). Fish and seafood also have this effect.
Vitamin C (ascorbic acid): a water soluble vitamin present in fruit and vegetables is known to enhance the absorption and availability of non-haem iron.
Similarly there are dietary components that reduce the amount of iron we can absorb:
Phytates: we consume most phytates in our diet from wholegrain cereals, but are also present in nuts, seeds and legumes. They inhibit non-haem iron absorption. Therefore a diet high in fibre can also have a negative impact on iron status (but high fibre intake is important for a healthy digestive system and provides other essential micronutrients!). Phytates can be reduced by processes such as fermentation, cooking, heat and soaking and vitamin C can counteract the effects of phytates on iron absorption.
Polyphenols: found highest in black tea, but also present in coffee, cocoa and herbal teas in smaller amounts. Again they inhibit iron absorption from foods, so it is best to avoid drinking tea whilst eating an iron rich meal.
Calcium: is known to interfere with iron absorption. So ensure calcium rich foods are consumed throughout the day to minimise the negative effect they have on iron absorption.
Soy protein: also impacts on non-haem iron absorption.
An individuals iron status (how much iron is stored in the body) also influences non-haem iron absorption.
More research is required to delve deeper into the dietary components that are thought to reduce and increase iron absorption.
DO I NEED TO TAKE AN IRON SUPPLEMENT?
Women of child bearing age and teenage girls are more likely to be iron deficient/or have low iron status than men of the same age, and the latest NDNS data confirms this. If you feel you may be at risk of iron deficiency visit your GP who will be able to establish your iron status and advise if you should take an iron supplement (if so take alongside a food rich in vitamin C, a small glass of orange juice for example, or a vitamin C supplement).
However a varied diet incorporating lots of dark green veg, pulses, wholegrains, nuts and in moderation red meat (if not vegetarian/vegan) will ensure iron intake is as sufficient as possible.
Article written by Lucy Vickers (RNutr) and Evie Lovell (ANutr).
