Understanding Causes, Symptoms, and Treatment Options of Carnitine Deficiency

Review Article

Abstract

Carnitine is a water-soluble quaternary amine involved in fatty acid oxidation. Defects in carnitine homeostasis can result in carnitine deficiency, a condition characterized by low carnitine levels and systemic metabolic abnormalities. Carnitine deficiency can occur due to primary defects in carnitine transport or secondary to underlying diseases that increase carnitine demand or impair synthesis. A lack of carnitine transporters or synthesis enzymes can limit carnitine uptake and recycling, depleting body stores. Insufficient carnitine impairs mitochondrial fatty acid breakdown, causing accumulation of toxic intermediates like acylcarnitines and ammonia. This can induce symptoms including fatigue, muscle weakness, hypoglycemia, and cardiomyopathy. At-risk populations include individuals on long-chain fat-restricted diets or parenteral nutrition, and those with inborn errors of metabolism. While carnitine supplements may benefit some patient groups, further research is needed to fully evaluate efficacy, optimal dosing, and long-term safety