It's hard to believe but in Australia 33-75% of infants and 19-25% of toddlers have inadequate iron intakes.
In infants, lower intakes are seen in those who are breast fed currently and in girls.
For toddlers, intakes are lower in children introduced to solids at later than six months of age. For preschoolers, iron intakes are lower in boys.
Does it matter?
Iron intake is of high importance because, if not addressed, iron deficiency can develop over time which can have some serious consequences.
Iron is essential for:
Transporting oxygen around the body
Energy production
Immune function
Cognitive functions
Enzyme functions
So what happens when a deficiency occurs?
Iron deficiency affects behavioural, psychomotor (the brain telling the body to move) and cognitive development.
Social /emotional behaviour abnormalities such as being difficult to soothe, engaging less socially or seeming to be less able to experience positive emotions like joy or contentment.
Delayed development of recognition memory
Poor academic achievement at school when deficiency was present in early childhood
Getting upper respiratory tract infections more often and them lasting longer.
Poor ability to regulate their own body temperature, reduced appetite, tiredness, reduced physical activity and even Pica (ie eating non foods such as soil, toys, grass).
How does iron deficiency happen?
Deficiency doesn't occur suddenly. We are all born with some iron stored in our bodies- enough to last up to six months since babies are fed milk in these early days which is low in iron. After that time we need to eat foods containing iron naturally, or foods which have had iron added (fortified foods) in order to replace those iron stores as well as have enough to be circulating in our bodies to perform all the usual functions of iron (see above).
At first when iron stores run out there are no symptoms but if the situation continues then red blood cell production is reduced and at the next stage we see depleted iron stores, low circulating iron and also severely reduced red blood cell production.
Can deficiency be fixed?
Yes, it can. Changing the diet to include more iron rich foods, including more animal foods and increasing fortified foods can all help. Iron supplements are the last resort since there is some evidence that they can negatively affect the gut microbiome.
However, if true deficiency has already had some of the effects detailed above on the child's development, these cannot be reversed. Prevention is therefore critical.
Who is most at risk?
Premature and low birth weight babies, babies born to women who are iron deficient themselves, males, babies and children in low socio-economic groups. Babies and toddlers with feeding problems. Babies and children with obesity or with inflammation or infections (these last ones all decrease ability to absorb iron).
Also, from a dietary perspective, young children on plant based diets, or who drink more than 500ml cows milk per day, those who had cows milk introduced before one year of age and those who are exclusively breastfed (no solids) after six months of age all have a higher risk. Why?
Cows milk is quite low in iron. It has also been shown to cause bleeding in the gut of children under one year (when milk is used as a drink rather than as a component of a meal), so that can reduce iron absorption. In terms of more than 500ml/day, it is simply a matter of milk being filling and so the baby/toddler is unlikely to be hungry enough for enough iron-rich foods as well!
Plant based diets
I am a big fan of plant based diets on the whole and a very large percentage of the Australian population would benefit from eating more whole grains, more vegetables, fruits, legumes, seeds and nuts.
For young children however, this approach to eating has to be balanced with the critical need for sufficient iron. Some plant foods do contain iron, but they are less easily absorbed than animal sources of iron and they often contain nutrients which lower or block absorption such as phytates, tannins, polyphenols and oxalates.
A vegetarian diet can supply enough iron but it's going to be a whole lot harder to achieve than with an omnivore (plants and animal foods) diet so careful planning will be needed.
Types of Iron
There are two types of iron in food. Haem and non haem. (You'll also see this spelt 'heme')
Haem iron is found in the flesh of animals: Red meat, poultry and fish. Non haem iron is found in plant foods and also non-flesh animal foods such as milk and eggs.
Iron absorption
It is easy to look up iron intake recommendations for different age groups and to assume that the foods that your child is eating supply enough. However, we need to consider that absorption of iron, even in healthy people is pretty low.
Infants typically absorb around 10% of the iron content of a food. Toddlers absorb on average 14% of the iron eaten and older children 18%.
Vegetarian toddlers recommended iron intakes should be increased by 40% and vegetarian older children should have their intakes increased by 80% over the recommended amounts due to the poor bioavailability of iron in purely vegetarian diets.
Which Iron rich foods are well absorbed?
Animal foods which contain iron are better absorbed because they contain none of the blocking nutrients which reduce absorption and due to a largely mysterious 'factor' which simply means that animal sources of iron increase absorption rates.
Obviously, flesh foods- meat- are the best iron source as they have blood in them and blood contains iron in the red blood cells.
Naturally not all young children are ready or willing to tuck into a steak but any flesh food- chicken, fish, mince etc. will have a good amount of iron. And the good news is that quite a small portion (for the sparrow-like eaters) provides enough iron for the meal.
How can absorption be enhanced?
The presence of vitamin C in foods enhances absorption of iron. So, if you serve plant foods which you know contain blockers then a fruit or vegetable rich in vitamin C served with it (or a squeeze of lemon or lime juice!) can help you to absorb more of the food's iron. Things like spinach are a conundrum- considered a good source of vegetarian iron, but also high in oxalates (a blocker) and vitamin C (an enhancer)! Best not to rely on spinach too much as major source of iron.
Interestingly, the body is pretty good at trying to solve its own problems so people low in iron actually absorb more of the iron from their food than people who are not deficient!
Which foods contain 'blockers'?
Phytates are found in grains, seeds, nuts and legumes so for example bread, pasta, nuts, sesame seeds, pumpkin seeds, peas and lentils. The higher the fibre content the higher the phytate content as phytatesare contained in the outer layers of grain which are removed in processing (eg wholemeal versus white flour).
Oxalates tend to be found in green leafy vegetables such as spinach but also beetroot, rhubarb, raspberries, sweet potato, almonds and celery.
Polyphenols are the tiny plant chemicals which often are responsible for the colour, strong smell or flavour of foods (eg beetroot, garlic, onion, berries).
Tannins We think of tannins in tea, coffee and wine but they are also present in spices, berries and some nuts.
Peptides in some milk proteins and in legumes such as chickpeas and beans.
As a group, for example in some vegetarian diets, these blockers even allowing for high vitamin C intake too, can lower iron absorption across the diet to as little as 5%.
Ensuring Iron Sufficiency
Introduce solids from six months of age including some iron fortified cereals and other animal products especially meat, poultry, fish in small amounts.
Don't introduce cows milk as a drink until after one year and don't allow toddlers to 'spoil their appetite' with too much milk.
Include meat, poultry. fish at several meals a day. Eggs are Ok too, but they are filling so they leave less room for other foods!
Include vitamin C containing fruits and veggies in main meals not just at snack time, as they can help to enhance iron absorption.
Consider including iron fortified foods (some breakfast cereals for example) if you struggle to include animal foods all the time.
Remember your children may not share your food preferences so a simple liver pate may be very acceptable to them even if not to you! (Top tip- Don't let on!)
Conclusion
There is a lot to take in when it comes to making sure your babies and children get enough iron. Just being aware is a great start. Eating a wide variety of foods is always a sound policy for any kind of nutritional sufficiency and that is where you should start.
I have not included national recommendations on daily intakes here as they are largely meaningless unless you are aware of the actual iron content of many foods.
If you feel strongly that meats should not be eaten then please seek the advice of a dietitian or nutritionist on how best to feed your baby or child.
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