Question: I am taking omega-3 fish oil (1000 milligrams a day) for my cholesterol. Is it okay that it contains cholesterol? — A.R., Honea Path

Answer: The key ingredients you should look for in omega-3 fish oil supplements are the amount of docohexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Nutritionist Kathy McManus recommends a combined dose of 500 to 1000 milligrams of DHA plus EPA daily.

DHA and EPA are important nutrients for the development of the nervous system during pregnancy and childhood, and essential for immune function, blood flow, heart rhythm and healthy skin.

You can get the same benefits by eating salmon, light tuna, catfish, mackerel, whitefish and other fatty fish. A deficiency of Vitamin E has been associated with taking fish oil supplements and many commercial products will contain Vitamin E, as well.

In a 2008 publication, the Mayo Clinic graded omega-3 fish oil a “D” in helping to reduce cholesterol. They report that fish oil can help lower triglyceride levels, but research does not support benefits for blood cholesterol levels.

You should discuss with your doctor how effective the supplement has been for lowering your cholesterol. If your doctor monitors your blood levels on a regular basis and the results indicate that your total cholesterol, high density and low density ratio and triglyceride levels are at healthy levels, then the omega-3 fish oil may be helping you.

An extensive study of omega-3 fatty acids reported in the British Medical Journal concluded that omega-3 fatty acids are not harmful, but do not provide the help against heart disease once claimed. Of course, this conflicts with earlier reports that associated the supplement with a reduction in heart attacks and strokes.

Question: After reading your article on vitamins and supplements, I wanted to send you information on a study comparing vitamin users. — M.H. (by e-mail)

Answer: Thank you for forwarding the study conducted by the School of Public Health at the University of California-Berkeley. This particular study examined a group of individuals who have taken multiple dietary supplements over 20 years. As you might expect, people who have taken multiple supplements for many years had better levels of nutrients in their blood and were less likely to have high blood pressure and diabetes. While that’s great news, the authors of the study conclude that other factors could play a role in the results. Lifestyles and dietary habits were not part of the study, nor was access to health care. The majority of multiple vitamin users were white, women, well-educated and at higher income levels. Information about exercise patterns was not reported, but weight was included and multiple vitamin takers tended to weigh less.

Before you start taking multiple supplements, talk with your physician and consider any prescription medication you take, as well as your general health. Good health also depends on what you eat and how much physical activity you get.