CoQ10 Biosynthesis
Every cell in the body has the ability to make coenzyme Q10 (CoQ10). However, not all cells make the same amount. The muscles, heart, kidneys, liver, and pancreas make the most coenzyme Q10 because these tissues require the most energy.
Adults store up to 2 grams of coenzyme Q10 in the body at all times. 1, 2 Of that amount, the body actually uses about 1/2 gram per day. Therefore, approximately 1/2 gram of coenzyme Q10 needs to be obtained daily either from the diet or biosynthesis (made by the body). 3 Some scientists believe that the primary source of coenzyme Q10 is biosynthesis.
Coenzyme Q10 is made through a long and complex series of biochemical reactions that requires both vitamins and minerals including: vitamin B6, vitamin C, vitamin B2, folic acid, vitamin B12, niacinamide, pantothenic acid, and trace elements. The simplified diagram below illustrates the pathway that the body uses to make coenzyme Q10. Interestingly, the body also makes cholesterol from this pathway. (This is important for people who take drugs to lower their cholesterol).
Causes of reductions in coenzyme Q10 include decreased production, increased utilization, or a combination of the two. The body’s average production of coenzyme Q10 gradually declines with age. Peak serum concentrations occur at 19-21 years of age and can drop 65% by age 80! 2 Tissue concentrations similarly decline with age as shown in the study below looking at coenzyme Q10 concentrations in the heart.
Decreased production can be a result of inadequate dietary intake of the vitamins and minerals required to make coenzyme Q10 due to chronic malnutrition or extreme dieting. Certain drugs have also been associated with reduced coenzyme Q10 levels. Of these, statins are the best documented. Individuals at risk for heart disease due to high cholesterol are often prescribed “statin” drugs to lower their cholesterol by blocking the enzyme HMG-CoA reductase in the synthetic pathway that converts HMG-CoA to mevalonic acid. As can be seen in the diagram above, reduction of cholesterol by blocking this step will also reduce the production of coenzyme Q10. Some doctors believe that the reduction in coenzyme Q10 associated with statin use may contribute to undesirable side effects such as fatigue and muscle weakness. Other medications that have been associated with reduced coenzyme Q10 levels include beta-blockers, used to treat heart disease and high blood pressure, and some oral anti-diabetic agents. Environmental stress, strenuous exercise, and various disease processes including congestive heart failure (CHF), cardiomyopathy, AIDS, cancer, hypertension and periodontal (gum) disease have also been reported to have coenzyme Q10 reductions. Increased utilization of coenzyme Q10, has also been suggested to occur with excessive exercise, hyper-metabolism, and acute shock states. Finally, reduced levels of coenzyme Q10 can be caused by any combination of the problems described above.In addition to biosynthesis, coenzyme Q10 can be consumed in the diet and can also be obtained from dietary supplements.
References:
- Bliznakov EG, Wilkins DJ: Biochemical and clinical consequences of inhibiting Coenzyme Q10 biosynthesis by lipid-lowering HMG-CoA reductase inhibitors (statins): A critical overview. Advances in Therapy 1998;15(4):218-28.
- Kalen A, Appelkvist E-L, Dallner G: Age related changes in the lipid composition of rat and human tissue. Lipids 1989;24:579-584.
- Ernster L, Dallner G. Biochemical, physiological and medical aspects of ubiquinone function. Biochim Biophys Acta 1995;1271:195-204.