In the primary healthcare setting, the most commonly seen causes of vitamin B12 deficiency are related to abnormalities of digestion (atrophic gastritis, achlorhydria or the consequences of gastrectomy) or absorption (autoimmune pernicious anaemia, chronic pancreatitis, Crohns disease, the effect of medications that alter the mucosa of the ileum, or the consequences of surgical resection), and, to a lesser extent, a lack of exogenous supply
Nicotinamide riboside neutralizes hypothalamic inflammation and increases weight loss without altering muscle mass in obese rats under calorie restriction: a preliminary investigation
Fras et al., The Lancet (2018): Major clinical investigation examining Tirzepatide's role in glucose regulation and metabolic impact
Semaglutide levels are not routinely measured in clinical practice in the UK
These are rare at the doses used in supervised clinical care and when they occur, they're typically mild and transient