Approximate dose-response bands. Individual response varies — these are starting points, not prescriptions.
Well below target. Risk of deficiency symptoms tied to fat oxidation.
Below the recommended daily target. Long-term adequacy not assured.
Daily target met. Standard nutritional support for fat oxidation.
Common for specific health goals. Check the evidence for your situation before sustaining this level.
Past the point where extra intake typically helps. Evidence for further benefit is thin.
You're at 0% of your l-carnitine target. The biggest single-serving sources to top it off:
Synthesised from lysine and methionine; required to shuttle long-chain fatty acids across the inner mitochondrial membrane for beta-oxidation. Adequate in unrestricted omnivorous diets; vegan/vegetarian intake is much lower but synthesis usually compensates. Therapeutic interest in cognition, neuropathy, and male fertility.
CPT-1 on the outer mitochondrial membrane swaps CoA for carnitine on long-chain fatty acyl-CoA; the resulting acylcarnitine crosses into the matrix where CPT-2 swaps back to acyl-CoA for beta-oxidation. Without adequate carnitine, long-chain fatty acids accumulate in cytoplasm and ATP production from fat falls — explaining the muscle weakness and cardiomyopathy of inherited carnitine deficiency.
Primary deficiency is rare (transporter defect). Secondary deficiency from valproate therapy, hemodialysis, severe malnutrition, or strict vegan diet over long periods.
Generally well-tolerated. High doses can produce 'fishy odour' (TMAO metabolite). TMAO controversy: gut bacteria convert carnitine to TMAO, hypothesised CV-risk linkage — clinical relevance still debated.
L-carnitine tartrate (gym/recovery), L-carnitine fumarate, or acetyl-L-carnitine (cognition and neuropathy). 500–2,000 mg/day in divided doses. Take on empty stomach for absorption.
Oral L-carnitine: ~15% bioavailable (active transport saturates quickly). Pharmacologic doses depend more on passive diffusion. Acetyl-L-carnitine has slightly better gut absorption and crosses BBB more readily. Carbohydrate co-ingestion increases muscle carnitine uptake (insulin-mediated).
Mitochondrial function is central to aging biology; carnitine supports fat oxidation and acetyl-CoA buffering. Direct longevity evidence in humans is thin; the TMAO question keeps the long-term supplementation case unresolved.
Fatty-acid transport into mitochondria; energy metabolism. Common dose 500–2000 mg.
The mechanisms and systems this nutrient feeds. Click any to drill into what runs on it.