DHA (docosahexaenoic acid) for fertility

On this page

1. What is DHA?
2. Function and how it works
3. Fertility benefits
4. Recommended daily dose
5. Food sources
6. Cautions and contraindications
7. My Fertility Guide
8. Related pages

1. What is DHA?

Docosahexaenoic acid (DHA) is a long-chain omega-3 fatty acid that is the dominant structural fat in the brain, retina and the membranes of egg and sperm cells. Together with eicosapentaenoic acid (EPA), DHA is the most studied omega-3 in human nutrition. While the body can convert short-chain omega-3 (alpha-linolenic acid, ALA) from plant foods into DHA, the conversion rate is very low (typically < 5%), so direct DHA intake from oily fish or algal supplements is recommended for fertility and pregnancy.

Reference ranges and recommended intakes vary from country to country — always interpret guidance against the recommendations of your own healthcare authority.

2. Function and how it works

DHA supports fertility through:

1. Egg and sperm membrane integrity. DHA is the primary fatty acid in egg and sperm cell membranes; adequate DHA is essential for fluidity, fertilisation and embryo development.
2. Anti-inflammatory action. DHA is the precursor to specialised pro-resolving mediators (resolvins, protectins) that resolve inflammation.
3. Sperm quality. DHA improves sperm count, motility and morphology.
4. Foetal brain and eye development. DHA is concentrated in the foetal brain and retina from the third trimester onwards.
5. Implantation and early pregnancy. DHA supports a healthy uterine lining and implantation.

3. Fertility benefits

DHA is particularly useful for:

1. Couples preparing for natural or assisted conception
2. Men with poor sperm count, motility or morphology
3. Women with PCOS, endometriosis or chronic inflammation
4. Vegans and vegetarians (who tend to have low DHA status)
5. Women preparing for and during pregnancy

4. Recommended daily dose

I recommend a combined intake of 500–1,000 mg of EPA + DHA per day for fertility, of which at least 200–300 mg should be DHA. During pregnancy, prioritise DHA at 200–500 mg per day. Choose a high-purity fish oil (third-party tested for heavy metals and PCBs) or algal DHA for vegan options.

5. Food sources

The richest food sources of DHA are:

1. Oily fish (salmon, sardines, mackerel, herring, anchovies) — 2–3 portions per week
2. Cod liver oil
3. Algal oil (vegan source)
4. Pasture-raised eggs (DHA-enriched)
5. Grass-fed beef and lamb (modest amounts)

Plant foods (flax, chia, walnuts) contain ALA, which the body must convert — the conversion is inefficient.

6. Cautions and contraindications

1. DHA has mild blood-thinning effects — do not combine with anticoagulant medication without medical supervision.
2. Stop high-dose fish oil at least two weeks before any planned surgery.
3. Choose products tested for heavy metals (mercury, lead) and PCB contamination.
4. Pregnant women should avoid large predatory fish (shark, swordfish, marlin, king mackerel) due to mercury content; choose smaller oily fish.
5. Always consult with a fertility specialist or your doctor before starting any new supplement regime.

7. My Fertility Guide

8. Related pages

• Fertility supplements directory
• Cod liver oil
• Vitamin D
• Vitamin E
• Coenzyme Q10