Read more about Vitamin B12: Side effects are simply " warnings " of what can go wrong when you are taking a vitamin, or any other supplement or prescription medication
Shanghai Arch
Front Pharmacol 12:693983 Zhu G, Deng Y, Feng J, Li Y, Chen L, Su Y, Ping A, Wang J, Xie F, Lv L (2024) "A preliminary study of thyroid hormones and thyroid ultrasonographic images in normal Chinese rhesus monkeys (Macaca mulatta)." Ziga D, Balasubramanian S, Mehmood KT, Al-Baldawi S, Salazar GZ (2024) "Hypothyroidism and cardiovascular disease: a review." Cureus 16(1)
Yet it cannot be ruled out that a response may be possible in a larger sample, a longer duration of supplementation, and/or a shorter assessment period (hoursdays versus weeks)
People on heavily restricted diets may also experience vitamin B12 deficiency