Carnitine Deficiency and Insufficiency in Medicine

Dr. Natsuki Nakayama earned his Ph.D. in 1980 for his research on the biogenesis of plant mitochondria. He subsequently joined Otsuka Pharmaceutical, where he conducted research in cardiovascular and diabetes pharmacology before moving into clinical drug development for cardiovascular therapeutics. In 2007, Dr. Nakayama began work on a specialized carnitine project. At that time, pharmaceutical-grade carnitine in Japan was approved solely for carnitine deficiency associated with methylmalonic acidemia and propionic acidemia. In 2011, he successfully broadened its indication to general “carnitine deficiency” without the need for clinical trials. He was further involved in the development of intravenous and oral liquid formulations, as well as in vitro diagnostic tools for identifying carnitine deficiency. Because the term “carnitine deficiency” entered the Japanese medical community rather abruptly, many physicians and medical staff were initially unfamiliar with the condition. To address this gap, Dr. Nakayama delivered hundreds of lectures across Japan, explaining the physiological role of carnitine and the clinical significance of carnitine supplementation in deficiency states. Through these extensive educational and outreach efforts, he has come to be recognized as a rare and distinctive expert in the science and clinical application of carnitine.