As with the cancer research, the effects of CLA on these conditions in humans remains unclear. CLA is found mainly in dairy products and also in beef and poultry , eggs , and corn oil. Bacteria that live in the intestine of humans can produce CLA from linoleic acid, but supplementation of a rich source of linoleic acid did not produce increases in blood levels of CLA in one human study. 13 CLA is available as a supplement. No deficiencies of CLA are reported or believed to occur, since it is not an essential nutrient.
Animal research uses very large amounts, equivalent to several grams per day for humans.
Until human research is conducted with CLA, the appropriate amount to take of this nutrient remains unclear. The side effects of CLA are unknown, due to the limited research in humans. However, one unpublished human trial reported isolated cases of gastrointestinal upset. At the time of writing, there were no well-known drug interactions with conjugated linoleic acid. For the convenience of the reader, the information in the table listing the supplements for particular conditions is also categorized.