B Vitamin Supplements
Also see our Top Pick among prenatal vitamins, which provides adequate (but not too much) folic acid, in our Multivitamin and Multiminerals Supplements Review.
CL has long warned that energy drinks and shots often contain large amounts of B6 and other B vitamins.
For more information, see ConsumerLab's answer to the question, I take omeprazole (Prilosec), a proton pump inhibitor, to reduce stomach acid. Are there supplements I should avoid, or be taking, due to this drug?.
For more details, see the updated reviews of B Vitamin Supplements & Energy Drinks and Protein Powders, as some of these products contain L-carnitine. The Acetyl-L-Carnitine Supplements review has also been updated because acetyl-L-carnitine is chemically similar to L-carnitine, suggesting a potential concern.