L-carnitine is responsible for maintaining energy metabolism in all the body's cells: it transports fatty acids across cell membranes to the mitochondria where they are ‘burned' for energy. As its name suggests, l-carnitine is only found in animal products, and at the maximum proportion of 100mg per 100g red meat. Vegetarians and those who rarely eat meat should therefore consider supplementation. L-carnitine:

• Helps each of the body's cells work at its optimal energy level
• Helps lower blood triglyceride levels
• Helps prevent certain cardiovascular diseases, particularly cardiac arrhythmia
• Helps weight loss when supplementation is combined with a low-carb diet
• Naturally increases energy levels
• Significantly improves performance in endurance sports and reduces muscular stress after exercise.

Sports enthusiasts, vegetarians and overweight individuals should opt to supplement with l-carnitine rather than the more expensive, ‘cerebroactive' acetyl-l-carnitine, or at least combine the two. US nutritionist Robert Crayon, who has written a best-seller on this ‘supernutrient', recommends combining l-carnitine and acetyl-l-carnitine in equal proportions. L-carnitine tartrate is a patented, non-hygroscopic and particularly stable form of l-carnitine.

Take 3 to 6 tablets a day spaced evenly throughout the day.