Final answer:
Gastric bypass surgery can alter the absorption of certain micronutrients like vitamin B12 and iron.
Step-by-step explanation:
After gastric bypass surgery, the absorption of several micronutrients can be altered. One example is vitamin B12, which is absorbed in the last part of the small intestine called the ileum. The surgery can bypass this section, leading to decreased absorption of vitamin B12. Another example is iron, which is normally absorbed in the duodenum. However, with the bypass, the duodenum is bypassed, resulting in reduced absorption of iron.