After Lap-Band and other purely restrictive procedures, nutritional levels remain stable
With restrictive procedures, such as the Lap-Band operation, the GI tract is essentially unaffected. Consequently, vitamin and micronutrient absorption remains intact. In these patients, we usually recommend a daily multivitamin. We assess serum levels to determine whether calcium and vitamin D supplementation might be necessary, which is especially important in female patients.
Close monitoring is needed after RYGB
After RYGB and other combined procedures, the question of nutritional supplementation becomes more complex.25 Bypass of the duodenum and upper jejunum affect absorption of iron, vitamin B12, calcium, and vitamin D. Serum calcium assessment is inadequate to determine the adequacy of calcium and vitamin D supplementation.
We evaluate parathyroid hormone and alkaline phosphatase levels in these patients. Any increase in these levels in the presence of normal serum calcium suggests the induction of secondary hyperparathyroidism and the need for additional calcium and vitamin D.26
Our recommendations for all patients following RYGB are a daily multivitamin, vitamin B12, and supplemental calcium and vitamin D. Vitamin B1 (thiamine) deficiency is extremely rare unless prolonged vomiting has been present. If B1 deficiency is suspected, administer thiamine before giving glucose because glucose can make symptoms worse.
Most women also need supplemental iron, which can be provided alone or in combination with the multivitamin, as in prenatal vitamins.
After RYGB, we measure vitamin and iron levels at 2 weeks, 3 months, 6 months, 12 months, 18 months, and then yearly thereafter unless a major abnormality is identified.