Riboflavin responsive multiple acyl-CoA dehydrogenase deficiency: functional evaluation of recovery after high dose vitamin supplementation.

The effect of riboflavin supplementation on muscle performance and exercise metabolism was investigated in four patients with multiple acyl-coenzyme A dehydrogenase deficiency (MAD). Maximum oxygen consumption and endurance measurements were performed to assess the patients' aerobic capacity and energy metabolism during exercise. They were tested before and after treatment with pharmacological doses of riboflavin. The initially low maximum oxygen consumption and high levels of blood lactate during submaximal exercise suggest that the oxidation of both fatty acids and carbohydrates was severely impaired. All four patients experienced a dramatic improvement in aerobic performance under riboflavin supplementation.