Fish oil doses vary depending on the goal of supplementation. For general health, 250 mg of combined EPA and DHA is the minimum dose and can be obtained via fish intake. The American Heart Association recommends 1 g daily.
Since fish oil is a combination of two different fatty acids, these numbers reflect a combined total. Total eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) consumption should come from a mix of real food and supplements. The more EPA and DHA is provided by the diet, the less supplementation is required.
Fish oil can be taken throughout the day. To minimize the "fish burp" taste, take fish oil with meals.
Pregnant women should increase their intake of DHA by at least 200mg a day, as long as there is no risk of elevated mercury levels.