Omega-3 fatty acids are essential for healthy growth and development in children and are generally safe. Oily fish is the best food source, but plant sources such as flaxseed can provide omega-3s too.

Some people choose to give children an omega-3 supplement, particularly if a child does not like eating fish. This approach may have potential benefits for learning, attention, and school performance.

In this article, we explain what omega-3 fatty acids are and how to consume them in food. In addition, we explore the correct supplement dosage for children and any potential safety issues of supplements.

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Omega-3 fatty acids are a group of polyunsaturated fatty acids that are essential to human health.

The body cannot produce omega-3s, so people need to get them from food.

The three main types of omega-3s are:

  • alpha-linolenic acid (ALA)
  • eicosapentaenoic acid (EPA)
  • docosahexaenoic acid (DHA)

ALA is present in some plant foods such as flaxseed, walnuts, and canola oil. DHA and EPA are present in fish and their oils.

Fish themselves do not synthesize the omega-3s. Instead, they accumulate them in their tissues by eating microalgae and phytoplankton, which synthesize them.

The human liver can convert ALA into EPA and DHA, but this conversion is limited, and possibly less than 15%.

Therefore, experts advise that people eat food that is a source of EPA and DHA or take a supplement to increase levels of omega-3s in the body.

The best food sources of DHA and EPA are oily fish such as:

  • salmon
  • sardines
  • mackerel
  • herring
  • anchovies
  • trout
  • tuna

Additionally, manufacturers fortify some foods such as eggs, yogurt, or milk with omega-3s.

It is important to check for bones when giving fish to children, as they may present a choking hazard.

Children can also take an omega-3 fish oil supplement. If a child follows a vegetarian or vegan diet, they can take a DHA and EPA supplement made from algae.

From birth to 2 years old, the brain grows most of its weight, but it develops fully throughout childhood and adolescence.

During these periods, omega-3 fatty acids, particularly DHA, are essential for children’s healthy growth, development, and school performance.

The following sections discuss this in more detail and look at what the evidence says.

Supports infant development

Supporting a child’s healthy development with omega-3s can start before a baby is born and continue while the child is in infancy.

According to the National Institutes of Health (NIH), better infant health outcomes may result if the infant’s parent consumes at least 8 ounces (oz) per week of seafood containing DHA during pregnancy and breastfeeding or chestfeeding.

DHA is vital for developing a child’s brain and retina and for healthy growth and birth weight.

The NIH adds that although seafood contains varying levels of methyl mercury, the health benefits of consuming moderate amounts of seafood during the prenatal period outweigh the mercury risks.

May improve ADHD symptoms

Omega-3s alter cellular membranes in the central nervous system and may help with brain processes in people with attention-deficit hyperactivity disorder (ADHD).

In a 2018 review, international experts advised that omega-3 supplements may produce small but significant reductions in ADHD symptoms while having a tolerable safety profile.

While the review also suggested additional benefits of omega-3s, including improved sleep quality and cognitive function, scientists need to do more research to confirm those.

According to the NIH, however, results for omega-3s benefitting ADHD are conflicting, although EPA and DHA may improve parent-rated oppositional behavior.

Potentially fewer allergies

In a study of 3,285 Swedish children, researchers found that regular fish consumption early in life may reduce the risk of allergies up to the age of 12, particularly rhinitis and eczema.

However, the NIH reports inconsistent results for studies that assess omega-3 and childhood allergies, suggesting that the association requires further study.

May improve sleep and school performance

Omega-3s are essential for brain health, and some studies link their consumption to children’s sleep and performance.

For example, a 2014 study found that children in the U.K. had low blood levels of DHA, and a 16-week DHA supplement program led to fewer waking episodes and more sleep per night.

The researchers also indicated that around 40% of children in the United States might have a clinical level sleep problem and suggested omega-3s could be beneficial.

A 2020 study on Mexican adolescents found that those with higher levels of plasma DHA had a 30 minute longer sleep duration at weekends when school and work did not restrict when they had to get up. The authors suggest that a 20-30 minutes increase in sleep duration can be beneficial for academic outcomes.

In particular, children with low literacy and low omega-3 intakes may benefit most from omega-3 supplements, according to a 2014 review.

In addition, evidence from clinical trials in school-aged children suggested that supplementing with omega-3s can improve cognitive development and school performance in these children.

Some research indicates virtually no severe side effects of omega-3 supplementation, with dyspepsia and nosebleeds being the most common.

However, the Academy of Nutrition and Dietetics notes that scientists need to do more research to determine the full implications on the body of consuming omega-3 fats. They recommend that people talk to their child’s health care provider before giving the child any dietary supplements.

The FDA advises people to avoid eating fish with the highest mercury levels. These include:

  • king mackerel
  • marlin
  • shark
  • swordfish
  • bigeye tuna
  • orange roughy
  • tilefish

The Institute of Medicine (IOM) has not established specific intake recommendations for EPA and DHA. Instead, they recommend daily requirements for ALA or total omega-3s according to a child’s age:

  • 0.5 grams (g) total omega 3s from birth to 12 months
  • 0.7 g ALA for 1-3 years
  • 0.9 g ALA for 4-8 years
  • 1.2 g ALA for males and 1g for females for 9-13 years
  • 1.6 g ALA for males and 1.1 g for females for 14-18 years

Human milk contains omega-3s, so the IOM bases its recommendations from birth to 12 months on the equivalent intake for a breastfed or chestfed child.

According to the NIH, children only consume about 40 milligrams (mg) of DHA and EPA from foods. Supplements also contribute to children’s omega-3s, adding about 100 mg to their average daily ALA intake.

However, the Academy of Nutrition and Dietetics suggests offering children a variety of food sources of omega-3 to children before turning to supplements.

For example, they suggest serving fish in kid-friendly ways such as salmon sliders, fish cakes, or baked fish nuggets. People can also add flaxseed oil to soups and casseroles and chia seeds to baked goods.

The FDA notes that for children, a serving size of fish is one ounce at age 2, increasing to four ounces by age 11.

Children need omega-3s for healthy growth, development, and brain function.

In addition, some evidence suggests that omega-3s may be beneficial for avoiding allergies, improving sleep and school performance, and mitigating ADHD symptoms. However, scientists need to conduct more research on those fronts.

Caregivers can include oily fish in children’s diets or turn to plant sources such as flaxseed for children who don’t eat fish.

Alternatively, children can take an omega-3 supplement, but should check with their doctor first. Moreover, children should avoid eating fish that have high mercury levels.