DHA, which stands for docosahexaenoic acid, is an omega-3 fatty acid that plays a key role in normal brain development in children, according to a 2013 review in "Nutrients." DHA is found in select foods; however, some of these foods may be contaminated with toxins, such as mercury. The usual intake of DHA among children is low, note authors of the 2013 review in "Nutrients."
Milligrams Per Pound
Although there is no universal guideline for daily DHA intake among children, recommendations do exist for combinations of DHA plus eicosapentaenoic acid, or EPA. According to the American Pregnancy Association, the International Society for the Study of Fatty Acids and Lipids suggests children ages 1 1/2 to 15 years get 15 milligrams of DHA plus EPA for each pound of their body weight daily, which is 600 milligrams of combined DHA plus EPA per day for a 40-pound child.
Amounts in Research
DHA supplementation in children has part of numerous research studies examining effects of DHA supplements on childhood development. The 2013 review in "Nutrients" reports that some studies show that supplementing with polyunsaturated fats, including DHA, has shown improvements in childhood cognition and behavior. Authors of this review point out that many studies involving children with learning disorders used supplements containing about 600 milligrams of DHA, but the optimal DHA dose for healthy children is unknown.
The main dietary sources of dietary DHA are coldwater fatty fish and seaweed, according to the University of Maryland Medical Center. Harvard School of Public Health notes that the human body can also make DHA – in small amounts – after consuming foods rich in alpha-linolenic acid, or ALA. ALA is found in walnuts, soybeans, canola oil and flaxseed. According to MedlinePlus, 3.5 ounces of fatty fish, such as salmon, tuna, anchovies and sardines, provide about 1,000 milligrams of omega-3 fatty acids, including DHA. However, children should consume no more than 12 ounces of low-mercury fish per week due to toxins – such as mercury – present in fish, suggests the U.S. Food and Drug Administration.
Because the mercury in fish and seafood, when consumed in excess, can negatively affect a child's cognitive development, some parents consider DHA supplements. Fish oil or vegan algae-based DHA supplements are generally rich in DHA. Many of these supplements undergo a purification process that eliminates harmful levels of contaminants such as mercury. However, small amounts of toxins might still be present in DHA supplements. Moreover, excess fish oil may increase a child's bleeding risk. Never give a child a DHA, or any other, supplement unless under a pediatrician's supervision.
- Nutrients: The Relationship of Docosahexaenoic Acid (DHA) with Learning and Behavior in Healthy Children: A Review
- American Pregnancy Association: Omega-3 Fish Oil and Pregnancy
- University of Maryland Medical Center: Docosahexaenoic acid (DHA)
- Harvard School of Public Health: Ask the Expert: Omega-3 Fatty Acids
- MedlinePlus: Fish Oil
- U.S. Food and Drug Administration: What You Need to Know About Mercury in Fish and Shellfish