Fatty acidLong-chain omega-3 fatty acid

DHA

Also known as Docosahexaenoic acid, 22:6 n-3

DHA (docosahexaenoic acid) is a long-chain omega-3 fat and a major structural building block of the brain, nervous system, and the retina of the eye. It is found in oily fish and algae, and it is especially important during pregnancy and infancy.

Classification
Long-chain omega-3 fatty acid
Type
Fatty acid
Grounded in the IOM/NASEM Dietary Reference Intakes and reputable nutrition science.

Why it matters

What it does in your body

  • Major structural fat in the brain and nervous system
  • Builds the retina and supports vision
  • Critical for fetal and infant brain development
  • Supports heart health

Intake guidance

How much you need

There is no formal Adequate Intake for DHA in adults, but the common suggestion is about 250 to 500 mg/day of DHA and EPA combined, met with two servings of fatty fish per week. Pregnant and breastfeeding women are often advised to get at least 200 mg of DHA per day for fetal and infant brain development.

What affects it

What affects your intake

Pregnancy and infancy

DHA is laid down rapidly in the developing brain and eye, so needs are emphasized in pregnancy, breastfeeding, and infant formula.

Fish and algae intake

Oily fish and algae oil are the direct sources; the body makes very little DHA from plant ALA.

Vegan diets

Because DHA comes from marine sources, vegans often rely on algae oil to get it directly.

In practice

Good to know

Good to know: DHA is the omega-3 that literally builds brain and eye tissue, which is why it is added to infant formula and recommended in pregnancy. Since the body barely converts plant ALA into DHA, fish or algae oil is the dependable route. For most adults, regular fatty fish covers it.

Where to get it

Best food sources

Salmon, 3 ozhigh in DHA and EPA
Sardines, 3 ozhigh in DHA and EPA
Herring, 3 ozhigh in DHA and EPA
Algae oil supplementa vegan DHA source
DHA-fortified eggs, 1 largemodest amount

The bottom line

DHA is a structural brain and eye fat that matters most in pregnancy and infancy. Get it from oily fish or algae oil, since plant omega-3 converts to DHA poorly.

Track dha automatically

DHA is one of the 92 nutrients Vora reads from a photo of your meal, so you can see where you stand without weighing or logging by hand.

Sources and method

The classification, roles, and guidance on this page come from the references below, drawing on the Institute of Medicine (now the National Academies) Dietary Reference Intakes and reputable nutrition science.

  • NIH Office of Dietary Supplements, Omega-3 Fatty Acids Fact Sheet for Health Professionals
  • American College of Obstetricians and Gynecologists

This page is for general education, not medical advice. Reference intakes are population averages for healthy people and do not replace guidance from your doctor or a registered dietitian, especially if you are pregnant, managing a health condition, or considering supplements.