Serum l carnitine and vitamin D levels may be low among oral sildenafil citrate non responders International Journal of Impotence Research Propionyl L Carnitine Erectile Dysfunction: What the Evidence Actually Shows Cohealon (Propionyl L Carnitine HCL) 333 mg 90 Tablets Ecological Formulas PureFormulas Propionyl L carnitine analytical standard 20064 19 1 Erectile Dysfunction Conditions & Causes Urology of Virginia: A Practical Look at Nutritional Support Options Icarifil, a Natural Mixture Based on L Citrulline and L Carnitine as a Novel Multicomponent Nutraceutical to Modulate ROS and PDE5