The brain grows faster in the first years of life than at any other time. By age five, a child's brain has reached approximately 90 percent of its adult size. By age three, it has already formed more than 1,000 trillion synaptic connections. This extraordinary period of neural development requires specific raw materials, and one of the most critical is DHA, a long-chain omega-3 fatty acid that the developing brain cannot function without.
Most children in North America do not get enough DHA. The dietary sources are limited to fatty fish, which most children eat infrequently if at all, and the body's ability to convert plant-based omega-3s into DHA is too inefficient to compensate. The result is a widespread nutritional gap during the most important period of brain development in a child's life.
Here is what the research shows about why omega-3 matters for children, what it does at each stage of development, and what to look for in a supplement.
What DHA Does in the Developing Brain
DHA (docosahexaenoic acid) is the dominant structural fatty acid in the brain, making up approximately 30 to 40 percent of the fatty acids in the cerebral cortex and 50 to 60 percent of the fatty acids in the retina of the eye. It is not simply a fuel source. It is a structural component of neuronal cell membranes that determines how efficiently neurons communicate with each other.
Neuronal membranes rich in DHA are more fluid and flexible, allowing ion channels, receptors, and signaling proteins to move and function more efficiently. This membrane fluidity directly influences the speed and precision of synaptic transmission, which is the fundamental mechanism of all brain function including learning, memory, attention, and emotional regulation. When DHA is in short supply, neuronal membranes become less fluid, synaptic efficiency declines, and the brain's ability to form and strengthen the connections that underlie learning is impaired.
DHA also plays a direct role in neurogenesis, the formation of new neurons, and in the myelination of nerve fibers. Myelin is the fatty sheath that insulates nerve fibers and dramatically increases the speed of nerve signal transmission. Myelination is a process that continues throughout childhood and into early adulthood, and it requires adequate DHA for optimal completion. Delays or deficiencies in myelination are associated with slower processing speed and reduced cognitive performance.
The retina's dependence on DHA is equally significant. Visual acuity, contrast sensitivity, and the ability to track moving objects all depend on the DHA content of photoreceptor membranes. Studies have found that children with higher DHA status have better visual acuity, and DHA supplementation in infancy has been shown to improve visual development outcomes.
The Critical Window: From Pregnancy Through Early Childhood
DHA accumulates in the fetal brain at an accelerating rate during the third trimester of pregnancy, when the brain undergoes its most rapid growth. This accumulation continues at high rates through the first two years of life, which is why breast milk is naturally rich in DHA and why infant formula is now required to contain DHA in many countries.
The consequences of DHA deficiency during this critical window are well documented. Studies have found that infants with higher DHA status, whether from breast milk, formula, or supplementation, show better performance on tests of visual acuity, problem-solving, and cognitive development in the first years of life. A landmark study found that children whose mothers had higher DHA intake during pregnancy scored significantly higher on tests of verbal intelligence, fine motor skills, and social development at age four.
The critical window does not close at age two. Brain development continues throughout childhood and adolescence, with significant periods of synaptic pruning, myelination, and prefrontal cortex development extending into the mid-twenties. DHA remains essential throughout this entire period, though the rate of accumulation is highest in the earliest years.
School Age: Focus, Reading, and Behaviour
The research on omega-3 and school-age children is extensive and covers several areas of particular concern to parents.
On attention and focus, multiple studies have found associations between low omega-3 status and attention difficulties in children. A randomized controlled trial published in the Journal of Child Psychology and Psychiatry found that omega-3 supplementation significantly improved attention, hyperactivity, and impulsivity scores in children with attention difficulties. A meta-analysis of 16 randomized controlled trials found that omega-3 supplementation produced significant improvements in inattention and hyperactivity in children, with effect sizes that were meaningful relative to behavioral interventions.
On reading and learning, a large study of school-age children in the UK found that those with lower blood DHA levels performed significantly worse on reading tests, and that DHA supplementation improved reading ability in children who were underperforming. A randomized controlled trial found that children taking omega-3 supplements showed significantly greater improvements in reading speed and accuracy over 16 weeks compared to placebo.
On behaviour and emotional regulation, omega-3 fatty acids influence the production and function of neurotransmitters including serotonin and dopamine, which regulate mood, motivation, and impulse control. Studies have found that children with higher omega-3 status show better emotional regulation, lower rates of aggressive behaviour, and better social functioning. A trial in children with behavioural difficulties found that omega-3 supplementation significantly reduced aggressive behaviour and improved prosocial behaviour over three months.
On sleep, DHA is involved in the production of melatonin, the hormone that regulates the sleep-wake cycle. A study found that children with higher DHA status had longer sleep duration and fewer night wakings, and that DHA supplementation improved sleep in children with low baseline DHA levels.
Why Diet Alone Is Not Enough for Most Children
The primary dietary sources of DHA are fatty fish including salmon, mackerel, sardines, and herring. Most children in North America eat these foods rarely if at all. Surveys consistently find that children's omega-3 intake falls well below recommended levels, with average DHA intake in children estimated at a fraction of the amounts associated with optimal cognitive outcomes in research.
Plant-based omega-3 sources including flaxseed, chia seeds, and walnuts contain ALA (alpha-linolenic acid), a short-chain omega-3 that the body can theoretically convert to DHA. In practice, this conversion is highly inefficient, with less than 0.5 percent of ALA typically converted to DHA in children. Relying on plant-based omega-3s to meet a child's DHA needs is not a viable strategy.
The gap between what children need and what they typically get from diet is one of the most consistent findings in pediatric nutrition research. Supplementation is the most practical way to close it.
What to Look for in a Children's Omega-3 Supplement
Not all children's omega-3 supplements are equivalent. Several factors determine whether a product will actually deliver meaningful DHA to a child's brain.
DHA content is the most important variable. Children's omega-3 supplements vary widely in their DHA to EPA ratio. For brain development and cognitive function, DHA is the primary active compound. A supplement with high DHA relative to EPA is more appropriate for children than one that simply maximizes total omega-3 content. Look for a product that specifies DHA content clearly and prioritizes it.
The triglyceride form matters for absorption. Omega-3s naturally occur in triglyceride form in fish, and this is the form the body absorbs most efficiently. Many fish oil supplements are processed into ethyl ester form to concentrate the omega-3s, which reduces bioavailability by approximately 70 percent compared to triglyceride form, particularly when taken without food. The re-esterified triglyceride (rTG) form combines the high concentration of ethyl ester processing with the bioavailability of natural triglycerides, making it the optimal form for children's supplementation.
Palatability determines compliance. A supplement that children refuse to take provides no benefit. Chewable softgels in a natural fruit flavor that children actually enjoy are far more likely to be taken consistently than capsules or liquid oils with a strong fishy taste. Natural orange flavor from real fruit sources, without artificial sweeteners or colors, is the appropriate standard for a children's supplement.
Purity and sourcing matter for a product given to children daily. Fish oil can accumulate environmental contaminants including heavy metals and PCBs if not properly purified. Third-party testing for contaminants and a clear sourcing statement provide meaningful assurance about what a child is actually consuming.
Kids Omega-3 | High DHA Fish Oil | rTG Form | Orange Flavour | 120 Chewable Softgels provides high-DHA omega-3 in the rTG form for optimal absorption, in a natural orange-flavored chewable softgel that children can take easily. Multi-pack options are available for ongoing daily use: 3-Pack (360 softgels) and 2-Pack (240 softgels).
How Much and How Often
Dosing recommendations for children's omega-3 vary by age and body weight. General guidance from nutritional research suggests that children aged two to twelve benefit from approximately 250 to 500mg of combined DHA and EPA per day, with DHA being the priority. Teenagers approaching adult body weight may benefit from doses closer to the adult range of 500 to 1,000mg per day.
Consistency matters more than timing. The brain's DHA content reflects long-term intake rather than acute supplementation, so daily use over weeks and months is what produces meaningful changes in DHA status and the cognitive outcomes associated with it. Taking omega-3 with a meal that contains some fat improves absorption and reduces the likelihood of any fishy aftertaste.
Omega-3 supplementation is safe for children at standard doses with no significant adverse effects reported in clinical trials. It does not interact with common medications and is appropriate for long-term daily use. For children with fish allergies, algae-based DHA supplements provide a fish-free alternative, though these are less commonly available in child-friendly formats.
The window of greatest impact is early, but it is never too late to improve a child's omega-3 status. Whether a child is two or twelve, closing the DHA gap supports the brain development and cognitive function that will shape their learning, attention, and emotional wellbeing for years to come.