Final answer:
Vitamin supplements are needed after Roux-en-Y gastric bypass surgery because the surgery limits food intake and nutrient absorption, leading to potential vitamin deficiencies. Vitamin B12 supplementation is crucial as intrinsic factor production is decreased due to the reduced stomach size, which is necessary for its absorption.
Step-by-step explanation:
The best response from the nurse regarding why vitamin supplements are needed after Roux-en-Y gastric bypass surgery would be to explain that this type of bariatric surgery modifies the digestive tract to limit food intake and nutrient absorption. As a result, there can be a deficiency in essential vitamins, such as vitamin B12, which requires the intrinsic factor produced by the stomach for absorption. Because this surgery creates a smaller stomach pouch and bypasses a significant portion of the small intestine, including the duodenum where many nutrients are typically absorbed, patients need to take vitamin supplements to prevent nutrient deficiencies and maintain good health.
Vitamin B12 is particularly important as it's essential for the production of mature red blood cells and normal neurological functioning. Without sufficient intrinsic factor production due to a significantly reduced stomach size, oral vitamin B12 cannot be adequately absorbed, making injections or high-dose oral supplements necessary. Additionally, the patient's ability to absorb other vitamins such as A, C, and D may also be compromised due to the alterations in the intestinal tract.