CoQ10 and Heart Failure
Daily requirement for Coenzyme Q10

The normal (non-athlete) person in the United States needs approximately 3.5 milligrams of Coenzyme Q10 for the maintenance of good health and good fitness. As the body grows older, it can no longer produce enough Coenzyme Q10, and the deficit of Coenzyme Q10 must be replaced through the diet and through supplements.
Animal protein is the primary source of Coenzyme Q10 in the human diet, and the quantity of Coenzyme Q10 in animal protein is low.  The absorption of Coenzyme Q10 from food is also low.  Furthermore, much of the Coenzyme Q10 in animal protein is lost in the cooking processes. Consequently, the majority of adults (estimated 88%) in the United States who are into their 30s or older need a daily Coenzyme Q10 supplement.

Effective Coenzyme Q10 levels
Studies have shown that normal healthy adults need enough Coenzyme Q10 in their diets and their supplements combined to raise their plasma Coenzyme Q10 levels to at least 2.5 micrograms per milliliter.  Adults diagnosed with chronic heart failure or ischemic heart disease or low energy syndrome as well as adults taking statin medications need plasma Coenzyme Q10 levels closer to 3.5 micrograms per milliliter.
Coenzyme Q10 and heart disease
The severity of chronic heart failure and ischemic heart disease has been shown to be inversely correlated with plasma Coenzyme Q10 levels.  In other words, the more severe the heart disease, the lower the plasma Coenzyme Q10.  Fortunately, supplementation with Coenzyme Q10 over a two-year interval can improve the New York Heart Association classifications of heart failure patients by much as two classes.
It takes 300 milligrams per day of dietary and supplemental Coenzyme Q10 to push the plasma Coenzyme Q10 level to more than 3.0 micrograms per milliliter. For example, in the Q-Symbio study, 300 milligrams of Coenzyme Q10 per day increased the plasma Coenzyme Q10 level to 3.45 micrograms per milliliter.

Divided doses of Coenzyme Q10
The rate of absorption of Coenzyme Q10 decreases when the one-time dosage is increased. The absorption will be better if a person takes 200 milligrams of Coenzyme Q10 as two times 100 milligrams at different times during the day, with meals, always with meals that contain some fat.  Similarly, the person who wants to take 300 milligrams per day should divide the dosage up into three times 100 milligrams per day.

Exercise and Coenzyme Q10
Exercise seems to be a stimulus to the body to bio-synthesize more Coenzyme Q10.  We do not know of any hormonal stimuli to increase the body’s own production of Coenzyme Q10.  Increased  tissue and cellular metabolic demand appears to be the stimulus for the endogenous  production of Coenzyme Q10.