Fish Oil Risks

Fish oil possesses many benefits. According to the University of Maryland Medical Center, the omega-3 fatty acid present in fish oil may help a variety of conditions from heart disease and diabetes to depression and arthritis. Unfortunately, as with many other supplements, some adverse risks exist.

• One of the most common side effects of fish oil is its tendency to induce burping, according the U.S. National Library of Medicine. Other gastrointestinal problems caused by fish oil include heartburn, abdominal pain and diarrhea. However, when fish oil is taken with meals and the dosage is increased slowly, these side effects may be prevented.

Contamination

• Fish oil can increase the risk of exposure to mercury, dioxin and other environmental pollutants, according to the U.S. National Library of Medicine. These contaminants can be especially harmful to young children and women who are either pregnant or nursing. Fortunately, many manufacturers take steps to rid their oil of contaminants. Reputable fish oil manufacturers, according to the American Pregnancy Association, test their fish oils using third-party labs to ensure the purity of their fish oil.

Vitamin Deficiency

• Fish oil may lead to a vitamin E deficiency if taken for an extended period, according to the U.S. National Library of Medicine. To counteract this, many manufacturers will add vitamin E to their products. Unfortunately, if intake is not monitored, elevated vitamin E levels may occur.

Vitamin Overdose

• Some fish such as cod liver oil contain high amounts of the vitamins A and D. These fat soluble vitamins can be stored in the body for extended amounts of time, increasing the risk for toxicity. The NYU Langone Medical Center recommends that people taking fish oil supplements should make sure the fish oil's manufacturer has removed excess vitamin A and D.

Increased Chance of Bleeding

• Large doses of fish oil may increase the chance of excessive bleeding, leading to possible nosebleeds and blood in the urine. Fish oil can also interact with blood thinning medications such as aspirin and warfarin (Coumadin), further increasing the risk of bleeding.

Drug Interactions

• In addition to blood thinning medications, fish oil may interact with other medications. According to U.S. National Library of Medicine, fish oil may increase the effect of glucose lowering medications like insulin and metformin (Glucophage). Similarly, fish oil may increase the effect of blood pressure medications. Before taking fish oil, you should contact your health care provider to prevent adverse reactions.