The average dietary intake of coenzyme Q10 and coenzyme Q9 of the Danish population was determined, based on food consumption data from a national dietary survey. Selected food items in edible form were analyzed for the coenzyme Q content by HPCL with UV-detection, and their contribution to the total intake calculated. The effect of cooking was a 14-32% destruction of coenzyme Q10 by frying, and no detectable destruction by boiling. The average coenzyme Q10 intake of the Danish population was estimated to 3-5 mg/day, primarily derived from meat and poultry (64% of the daily intake), while cereals, fruit, edible fats, and vegetables only make minor contributions. The intake of coenzyme Q10 is approximately 1 mg/day, primarily derived from vegetable fats and cereals. The alpha-tocopherol content of the selected food samples was analyzed by HPLC with fluorescence detection, and the calculated average intake of alpha-tocopherol was comparable to the estimate from the dietary survey (7-8 vs. 7.4 mg alpha-tocopherol/day, respectively). The commercially available dietary supplements (capsules) provide 10-30 mg CoQ10/day, thus the average diet. The optimal dietary intake of coenzyme Q10 is unknown.