Saturday, August 4, 2007

Coenzyme Q10: Dietary Sources, Precautions

Coenzyme Q10 (CoQ10), also known as ubiquinone, is essential for energy production. It is an antioxidant—a molecule that has been shown to counteract processes resulting in disease.


Coenzyme Q10 deficiency primarily affects the heart and leads to heart failure. This deficiency can result from impaired coenzyme Q10 production or an increased need for it resulting from cardiovascular disease. Also, coenzyme Q10 levels may drop as we age.

A growing body of research shows that using a coenzyme Q10 supplement alone or in combination with other drug therapy may be beneficial in the treatment of several health problems, particularly cardiac conditions and diseases, breast cancer, diabetes mellitus, immune deficiency, muscular dystrophy, and periodontal disease.

Coenzyme Q10 supplementation may be of special interest to patients with high blood pressure. The supplement has a tendency to lower high blood pressure after 4 to 12 weeks of use.

Some cholesterol-lowering medications may deplete levels of coenzyme Q10 in the body, so people with high cholesterol who take these medications should also consider taking coenzyme Q10 supplements.

This supplement can also be used as a pretreatment for cardiac bypass surgery. It has been shown to reduce oxidative damage and protect the heart during surgery.

Dietary Sources

Coenzyme Q10 is found in every plant and animal cell. Primary dietary sources include oily fish, organ meats such as liver, and whole grains. Most people get enough coenzyme Q10 in their diet. Supplementation can be helpful in individuals with certain health conditions and in the elderly, because levels of coenzyme Q10 can decline with advancing age.

Other Forms

Coenzyme Q10 is available as a supplement in several forms, including softgel capsules, spray, hardshell capsules, and tablets.

How to Take It


There are no known reports to date about use of Coenzyme Q10 supplements in children. Therefore, use in children is not recommended at this time.


The general recommended dose for supplementation is 25 mg twice daily. Experimental doses include the following:

  • 100 mg a day in patients with heart disease
  • 60 mg a day for 4 to 8 weeks to enhance athletic performance
  • 120 mg a day for 28 days after a heart attack
  • 400 mg per day for potential prevention and treatment of breast cancer, and possibly other forms of cancer

Coenzyme Q10 should be taken with a meal containing oil since it is fat soluble. The body does not absorb it as well in the absence of oil.


Coenzyme Q10 appears to be safe with no significant side effects. However, the safety of supplementation during pregnancy and breastfeeding is unknown.

Possible Interactions

Coenzyme Q10 may help to reduce the toxic effects on the heart of daunorubicin and doxorubicin, two chemotherapy medications that are commonly used to treat a variety of cancers. Consult your healthcare provider before using coenzyme Q10 supplements while you are taking these medications.

In a scientific study, supplementation with CoQ10 in patients taking medications for high blood pressure (such as diltiazem, metoprolol, enalapril, and nitrate) resulted in the need for lower doses of these medications. More research is needed to verify these results; therefore, you should consult your healthcare practitioner before adding CoQ10 supplements to your existing medication regimen.

There have been reports that coenzyme Q10 may decrease the effectiveness of blood-thinning medications such as warfarin. Therefore, you should not use CoQ10 supplements if you are currently taking warfarin without discussing this with your healthcare provider.

In one study, treatment with CoQ10 in patients using timolol drops, a beta-blocker medication used to treat glaucoma, reduced side effects on the heart without decreasing the effectiveness of the medication. Consult your healthcare provider about whether CoQ10 supplements may be appropriate for you if you are being treated with timolol.

Please refer to the consumer depletions monographs for additional information on other medications that may reduce the levels of coenzyme Q10 in the body, such as gemfibrozil, beta-blockers, and tricyclic antidepressant medications, to name a few.

Supporting Research

Aberg F, Appelkvist EL, Broijersen A, et al. Gemfibrozil-induced decrease in serum ubiquinone and alpha- and gamma-tocopherol levels in men with combined hyperlipidaemia. Eur J Clin Invest. 1998;28:235-242.

Chan A, Reichmann H, Kogel A, Beck A, Gold R. Metabolic changes in patients with mitochondrial myopathies and effects of coenzyme Q10 therapy. J Neurol. 1998;245:681-685.

Chopra RK, Goldman R, Sinatra ST, Bhagavan HN. Relative bioavailability of coenzyme Q10 formulations in human subjects. Int J Vitam Nutr Res. 1998;68:109-113.

Haas EM. Staying Healthy with Nutrition. Berkley, Calif: Celestial Arts Publishing; 1992:65-79.

Iarussi D, Auricchio U, Agretto A, Murano A, Giuliano M, Casale F, et al. Protective effect of coenzyme Q on anthracylines cardiotoxicity: Control study in children with acute lymphoblastic leukemia and non-hodgkin lymphoma. Molec Aspects Med. 1994;15(Suppl):S207-S212.

Jolliet P, Simon N, Barre J, et al. Plasma coenzyme Q10 concentrations in breast cancer: prognosis and therapeutic consequences. Int J Clin Pharmacol Therapeu. 1998;36:506-509.

Kishi T, Kishi H, Wanabe T, Folkers K. Bioenergetics in clinical medicine. XI. Studies on CoQ and diabetes mellitus. J Med. 1976;7:307-321.

Landbo C, Almdal TP. Drug interaction between warfarin and coenzyme Q10. Ugeskrift for Laeger. 1998;160(22):3226-3227.

Lockwood K, Moesgaard S, Yamamoto T, Folkers K. Progress in therapy of breast cancer with vitamin Q10 and the regression of metastases. Biocehmical and Biophysical Research Communications. 1995;212(1):172-177.

Matthews RT, Yang L, Browne S, Baik M, Beal MF. Coenzyme Q10 administration increases brain mitochondrial concentrations and exerts neuroprotective effects. Proc Natl Acad Sci USA. July 21, 1998; 95:8892-8897.

Murray MT. Encyclopedia of Nutritional Supplements. Rocklin, Calif: Prima Publishing; 1996:296-308.

Murray MT, Pizzorno JE. Encyclopedia of Natural Medicine. 2nd ed. Rocklin, Calif: Prima Publishing; 1996.

Niibori K, Yokoyama H, Crestanello JA, Whitman GJ. Acute administration of liposomal coenzyme Q10 increases myocardial tissue levels and improves tolerance to ischemia reperfusion injury. J Surg Res. 1998;79:141-145.

Shils ME, Olson JA, Shike M, Ross AC. Modern Nutrition in Health and Disease. 9th ed. Baltimore, Md: Williams & Wilkins; 1999:90-92: 1377-1378.

Shinozawa S, Kawasaki H, Gomita Y. [Effect of biological membrane stabilizing drugs (coenzyme Q10, dextran sulfate and reduced glutathione) on adriamycin (doxorubicin)-induced toxicity and microsomal lipid peroxidation in mice]. Gan To Kagaku Ryoho. 1996;23(1):93-98.

Sinatra S. The Coenzyme Q10 Phenomenon. New Canaan, Conn: Keats Publishing, Inc.; 1998:127-129.

Singh RB, Niaz MA, Rastogi SS, Shukla PK, Thakur AS. Effect of hydrosoluble coenzyme Q10 on blood pressures and insulin resistance in hypertensive patients with coronary artery disease. J Hum Hypertens. 1999;13(3):203-208.

Singh RB, Wander GS, Rastogi A, et al. Randomized, double-blind placebo-controlled trial of coenzyme Q10 in patients with acute myocardial infarction. Cardiovasc Drugs Ther. 1998;12:347-353.

Spigset O. Reduced effect of warfarin caused by ubidecarenone. The Lancet. 1994;344:1372-1373.

Takahashi N, Iwasaka T, Sugiura T, et al. Effect of coenzyme Q10 on hemodynamic response to ocular timolol. J Cardiovasc Pharmacol. 1989;14:462-468.

Werbach M. Foundations of Nutritional Medicine. Tarzana, Calif: Third Line Press, Inc.; 1997:209.

Werbach MR. Nutritional Influences on Illness. 2nd ed. Tarzana, Calif: Third Line Press; 1993:66, 119, 122, 179, 421.

Zhou Q, Chan E. Accuracy of repeated blood sampling in rats: A new technique applied in pharmacokinetic/pharmacodynamic studies of the interaction between warfarin and Co-enzyme Q10. J Pharmacol Toxicol Methods. 1998;40(4):191-199.

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