Which deficiency are nonadherent patients following gastric bypass at risk for?

Nonadherent patients following gastric bypass surgery are at heightened risk for thiamine (vitamin B1) deficiency primarily due to several physiological changes that occur after the procedure. Gastric bypass significantly alters the normal digestive process by reducing the stomach's size and rerouting the small intestine. This can lead to decreased absorption of various nutrients, including thiamine, which is crucial for carbohydrate metabolism and neurological function.

Additionally, thiamine deficiency can be exacerbated in nonadherent patients who may not take recommended vitamin supplements or have irregular dietary habits post-surgery. A lack of compliance with vitamin supplementation can lead to serious clinical outcomes, including Wernicke's encephalopathy, which is characterized by confusion, eye movement abnormalities, and ataxia.

While deficiencies in the other vitamins may occur in patients post-gastric bypass, they are typically less common than thiamine deficiency, particularly in cases where adherence to dietary guidelines and supplementation is compromised. Therefore, the primary concern for nonadherent patients is the risk of thiamine deficiency.