Fish Oil- How Much and Which, EPA or DHA?
Use EPA predominant fish oil 2:1 or 3:1 ratio EPA/DHA for cardiovascular, neurodegeneration, psychiatry (depression, anxiety, bipolar, etc.) for adults at doses of 2-4 grams a day for heart and neurological benefit and 1-2 grams a day for psychiatry. Hence, I recommend 2 grams a day of mostly EPA fish oil for adults.
Fish oil has been found to be mood stabilizing for young children on par with the effectiveness of olanzapine and risperidone (higher EPA/DHA used).
For children with ADHD or neuropsychiatric issues, high dose EPA/ DHA (3:1) takes 6 months or longer and will reduce to baseline ADHD symptoms (must be EPA dominant). The ideal ratio is likely 3/1 EPA/DHA at 500-1500 mg daily for ages 3+. DHA dominant oils are for infants only, older kids need the higher EPA.
During pregnancy, taking fish oil reduces eczema and allergies in your child as they grow. Fish oil in pregnancy has been shown to help brain function, visual acuity, and hand-eye coordination (improved neurodevelopment). Studies would suggest that even in pregnancy, moms should take at least 300 mg of DHA but have also at least 600 mg of EPA. This protects mom from depression, and is more anti-inflammatory than just DHA oils. Pregnant moms will selectively transfer the DHA component to the developing baby in the womb and through breast milk.
As far as the question of how much fish oil can you give a newborn or infant, looking at the amount supplemented in formula, we give infants DHA dominant fish oil with studies showing up to 200 mg DHA safe for 1 month olds and up to 400 mg DHA for a 6 month old. A study on 9 month olds showed no side effects from giving 9 month olds 700 mg DHA with over 1000 mg EPA .