Studies have shown that regular intake of collagen supplements can improve skin hydration, elasticity, and texture, resulting in a smoother and more youthful appearance
The best sources include: Red meat (especially lamb and beef) Fish Poultry Dairy products Smaller amounts are found in some plant sources like avocado and asparagus, but generally, vegetarian and vegan diets provide less L-carnitine
Alsughayyir J, Alshaiddi W, Alsubki R, Alshammary A, Basudan AM, Alfhili MA
The use of CO for diagnostic purposes, such as total haemoglobin mass measurements or the determination of pulmonary diffusion capacity, is not prohibited
This is not proof of clinical harm at therapeutic doses, but it provides a plausible mechanistic basis for concern