DHA is a structural fat, and the brain and retina are built partly out of it. In the first couple of years a child's brain and eyes develop faster than at any other point in life, and where the DHA comes from keeps changing as they grow: from the mother before birth and during breastfeeding, then from formula, then from food.
Why DHA Matters in the First Few Years
DHA is one of the two long-chain omega-3s, and unlike most fats it doesn't get burned for energy. It gets built into the membrane of cells and stays there. It collects where membranes have to stay flexible and carry signals, which is why the brain and the retina of the eye hold so much of it.
That's why the timing matters. A baby's brain grows faster in the first two years than at any later point, and the raw material for that growth comes from what the baby is fed.
Experts agree that maternal intake of DHA contributes to the normal brain development of the foetus and breastfed infants, at 200 mg of DHA a day on top of the usual adult intake. And DHA contributes to the normal visual development of infants up to 12 months of age, at a daily intake of 100 mg.
Note who the first of those is about. Before birth and while breastfeeding, the intake that matters is the mother's, not the baby's.
SUMMARY: the brain and the retina are partly made of DHA, and once it's in a cell membrane it stays put. Most of that construction happens before a child turns two, and before birth and during breastfeeding the DHA doing it comes from the mother.
Where Do Babies Get Their DHA?
It depends entirely on how they're fed.
Breastfed. The DHA comes through breast milk, and how much is dependent on what the mother eats. A mother eating oily fish, or taking an algae oil supplement, passes more of it on. It should be noted, however, that pregnant women are advised to limit oily fish intake due to the risk of heavy metals.
Formula-fed. This one's settled by law. UK regulations require infant formula to contain DHA, at between 20 and 50 mg per 100 kcal [1]. So a formula-fed baby in the UK should be getting enough DHA.
If you're pregnant or breastfeeding, the intake that matters is yours. We developed a vegan omega-3 DHA and EPA from algae, and two capsules a day give you 300 mg of DHA and 150 mg of EPA. That's the extra 200 mg of DHA covered, with the ordinary adult intake underneath it. It's also algae rather than fish, so the heavy-metal caution above doesn't apply to it. There's more on all of this in our guide to omega-3 DHA for pregnancy.
SUMMARY: for the first six months a baby's DHA comes from milk. Breast milk carries as much as the mother's diet supplies, and formula has a legal minimum. So if you're breastfeeding, what you eat decides what they get.
What Changes at Six Months?
Everything, in feeding terms.
The NHS advises starting solid foods at around six months, and says that up to that point babies get most of their energy and nutrients from breast milk or first infant formula [2]. So for the first half-year, what your baby eats is mostly a question of what you eat, or what the formula contains.
Once weaning starts, that shifts. Milk gives way to food, and food is where the DHA now has to come from.
Worth knowing at the same time: the government recommends that all children aged six months to five years are given a daily supplement containing vitamins A, C and D [3]. Breastfed babies should have vitamin D from birth, and A, C and D from six to twelve months. Babies having more than 500ml of formula a day don't need them, because formula is already fortified [3].
Our Children's Multivitamin Gummies cover A, C and D along with vitamin E and four B vitamins, in a sugar-free strawberry bear that most children will take without an argument. They're suitable from age three, so they're ideal for toddlers. For younger children, the vitamin A, C and D drops the NHS describes are what you want.
Although official UK guidance covers vitamins A, C and D for young children and doesn't officially recommend an omega-3 supplement for them, we believe it to be important because of the role it plays throughout the body.
SUMMARY: weaning moves the job from you to the dinner plate. The government also recommends vitamin A, C and D drops from six months to five years, unless your baby is having more than 500 ml of formula a day.
Should Children Eat Fish?
Oily fish is the richest ordinary source of DHA, and the NHS advice is at least two portions of fish a week, one of them oily [4].
There are limits for children, though:
- Children under 16 should avoid shark, swordfish and marlin entirely, because the mercury in them can affect a child's nervous system [4].
- Tuna doesn't count as oily fish for these purposes [4].
If your child eats oily fish happily and regularly, they're getting DHA and this is largely a solved problem. Plenty of children don't.
Does My Child Need an Omega-3 Supplement?
It's worth considering if your child doesn't eat fish, whether that's because you raise them plant-based, because of an allergy, or simply because they won't touch it. No plant food contains DHA. Flaxseed, chia and walnuts give you ALA, and the body converts very little of that onward into DHA, so a child eating a plant-based diet isn't getting DHA from those foods in any meaningful amount.
Algae is the exception, and it's where the DHA in fish came from in the first place. Fish accumulate it by eating algae, or by eating something that ate algae.
For a baby under one, talk to your health visitor or GP before adding any supplement that isn't the recommended vitamin drops. For a child who's eating a full and varied diet, this is a straightforward parental judgement about whether fish is part of it.
SUMMARY: flaxseed, chia and walnuts give you ALA, and the body turns very little of it into DHA. Algae is the one plant food that already contains DHA, which is worth knowing if fish is never going to happen in your house.
How Much DHA Are We Talking About?
For infants up to twelve months, the figure attached to normal visual development is 100 mg of DHA a day. For everyone older, normal brain function and normal vision are set at 250 mg a day.
Our kids' omega-3 drops are made from algae rather than fish, in a dropper so you can measure a small dose. Each 1 ml carries 123 mg of total omega-3, of which 67 mg is DHA and 33 mg is EPA. The dosing on the bottle is 1 ml a day for ages three months to two years, and 2.5 ml a day from two to ten years, which works out at about 167 mg of DHA at the older dose.
They're orange-flavoured rather than fishy, and because algae is grown in closed tanks rather than caught, there's no question of the heavy metals that accumulate in fish.
The Bottom Line
DHA is structural, and the years when a child is building the most brain and eye tissue are when it matters most.
Before six months, that's your job rather than theirs: through breast milk, where it tracks your own intake, or through formula, which is required by law to contain it. After six months it comes from food, and oily fish is the everyday source.
If fish isn't part of your family's diet, algae is the only plant source that supplies DHA ready-made. And whatever you decide about omega-3, the vitamin A, C and D drops for the under-fives are the ones the government actually recommends.
