Coenzyme Q10 (CoQ10) is a fat-soluble compound with numerous vital functions. CoQ10 is mainly synthesized endogenously, but it can also be obtained from dietary intake. It exists in the body as ubiquinone, which is the oxidized form, and from ubiquinol, which is the reduced form. The name is derived from the word ubiquitous, meaning “found everywhere.” True to its namesake, CoQ10 is found in every cell in the body. 

One major role of CoQ10 is supporting adenosine triphosphate (ATP) production as an electron carrier in the mitochondrial electron transport chain. Another major role of CoQ10 stems from its potent lipid-soluble antioxidant properties. It protects cells against DNA damage and oxidative stress. Other functions of CoQ10, as shown in studies, include regenerating other antioxidants (such as vitamin C and vitamin E) and influencing gene expression. CoQ10 is produced mainly in the heart, skeletal muscle, liver, and kidneys, and approximately 50% of cellular CoQ10 is present in mitochondria. 

The daily requirement of CoQ10 is still being elucidated, however, is estimated at 500 mg per day. Only a small amount comes from dietary intake (approximately 5 mg). Endogenous CoQ10 synthesis approximately begins a steady decline at 25 years of age, which falls to approximately 50% of original levels by 65 years of age. The biosynthesis limitation of CoQ10 may also result from genetic mutations, pharmaceuticals, or illness. CoQ10 deficiency has been correlated to the pathogenesis of various disorders, potentially due to its connection with mitochondrial dysfunction. 

Mitochondrial dysfunction can result from numerous diseases and may impair ATP production and increase oxidative stress, inflammation, and endothelial dysfunction in the body. CoQ10 exhibits anti-inflammatory and antioxidative properties that can help to improve mitochondrial function. The positive impact of CoQ10 on mitochondrial health has been researched in patients with diabetic retinopathy, fibromyalgia, heart failure, cardiovascular disease, chronic obstructive pulmonary disease, chronic kidney disease, non-alcoholic fatty liver disease, and neurodegenerative diseases. 

A systematic review (n = 1,067) examined CoQ10 supplementation in patients with cardiovascular disease and hypertension. The authors concluded CoQ10 to be a safe, well-tolerated supplement that may reduce adverse cardiovascular event risk. One of the randomized controlled trials (n = 121) studied the impact of 300 mg per day of CoQ10 for 2 weeks in patients who were preparing to undergo cardiac surgery. The treatment group had a fourfold greater CoQ10 concentration than the placebo group and a statistically significant increase in mitochondrial efficiency and mitochondrial protection from oxidative stress at the time of surgery. 

Although CoQ10 is technically not a vitamin, it has been described as vitamin-like due to its essential function in every living cell of the body. The role of CoQ10 for mitochondrial function may result in clinically relevant benefits to various conditions and an overall general well-being. 

By Danielle Moyer, MS, CNS, LDN