A one year bioavailability study of coenzyme Q10 with 3 months withdrawal period.

Twenty-one healthy subjects received oral Coenzyme Q10 supplementation in soft capsules of 30 mg t.i.d. for 9 months, followed by a withdrawal period of 3 months. Blood samples were taken before start of supplementation, after 3 and 9 months of supplementation, and finally 3 months after withdrawal. Average blood coenzyme Q10 concentration increased from about 1 mg/l before supplementation to about 2 mg/l after 3 and 9 months of supplementation, and returned to the pretreatment level after withdrawal. The rise of coenzyme Q10 concentration was statistically significant (P < 0.001, t-test).