Iron deficiency can often be so subtle that a child can almost be anaemic and parents can miss it.
Grant says symptoms can include a child "not having as much energy as normal", having changes in behaviour like being "less happy" and being "more difficult to console". Other giveaways include a child looking "pale" to them having fingernails that are "rounded on top". Be on the alert too for a child getting lots of infections and remember growth spurts can lead to a child outstripping their iron stores.
Those at most high-risk are children up to 2, particularly those born premature or of a low birth weight, as well as teenage girls when they start their periods.
New Zealand has no national policy around supplementing iron, nor do we have any screening for it or recommendations for fortifying foods as in other countries.
Having your child's blood tested is the best way to find out categorically if your child is iron deficient but it is no easy task to get a child to agree to have a needle inserted into them.
But there are several ways to help combat iron deficiency, says Grant, including eating three to four servings of red meat weekly - which is more iron-loaded than fruit or vegetables. He says eating red meat with fruits or vegetables that contain vitamin C, such as oranges or orange juice, helps the body absorb iron best. He says parents should serve vegetables with meat, or give fruit for dessert to a young child after a meat meal, to help with iron absorption.
He says breast milk is best for babies, and recommends they eat cereals fortified with iron when old enough.
Celebrity chef and MasterChef judge Simon Gault says liver is super-high in iron - "so pate on crackers will do the trick really well".
He says a great recipe to get kids eating meat is to cook some green beans, refresh them in ice-cold water, dry them off and then roll them tightly in prosciutto and bake them until crispy, "Yum!"
Gault says eating fresh blueberries is an easy idea. He also advises parents to get their kids eating olives or the olive-loaded spread or dip, tapenade.
One way he recommends to "disguise" tapenade in a meal for children is to sneak it into chicken breasts before cooking. Simply use a sharp knife to slice fresh chicken open and push in tapenade or olives and cook "until crispy".
Parents should check out freeze-dried fruit and vegetable "chips" too to give to their kids as a snack to help them absorb more iron.
Cameron Grant's good sources of iron:
* Red meat is best. Three to four servings weekly.
* Chicken
* Fish
* Iron-fortified cereals
* Iron-fortified formila
* Green leafy vegetables and fruits. Many contain vitamin C which helps with the absorption of iron.
Top 5 ways to boost your child's brain power:
The new school terms has started. Give your kids a head start with ...
1. A good breakfast - wholegrain cereals and oats, eggs, kiwi fruit, blueberries and bananas are all great for a morning brain boost.
2. Brain yoga - a set of simple exercises as a workout for the brain. Controlled breathing techniques also increase oxygen flow to the brain.
3. The good oil - quality fish oil, with its omega-3 essential fatty acids, helps with concentration.
4. Interaction - conversations with your child and playing games and puzzles with them increases brainpower and vocabulary.
5. Visualisation - get your child to imagine the teacher's smile when they get the answers right: never underestimate the power of positive thinking.