Which statement about medium-chain triglyceride therapy in fatty acid oxidation disorders is correct?

• A. It requires the carnitine shuttle to enter mitochondria
• B. It can be absorbed and enter mitochondria without carnitine shuttling
• C. It is not metabolized for energy
• D. It worsens fat malabsorption

Answer: (B)

Medium-chain fatty acids can supply energy in fatty acid oxidation disorders because they bypass the carnitine shuttle to enter mitochondria. When long-chain fats can’t be efficiently transported into mitochondria, providing energy from medium-chain triglycerides helps maintain ATP production. Medium-chain fats are absorbed from the gut and reach the liver via the portal circulation, and they can be activated and oxidized inside mitochondria without relying on the carnitine transport system. This is why the correct statement is that it can be absorbed and enter mitochondria without carnitine shuttling. The idea that the shuttle is required is incorrect; these fats are indeed metabolized for energy, and they do not worsen fat malabsorption—in fact, they’re absorbed more readily than long-chain fats.