A Gastric Bypass is a first, courageous step towards a healthier life. Step two is to get fit and stay in balance. Vitamins and minerals are essential for this. But a weight loss surgery means that you can eat less and absorb fewer nutrients. A daily multivitamin prevents a vitamin and mineral deficiency. You also need extra calcium and protein to maintain strong muscles and bones. Therefore, we recommend the following multivitamins after a Gastric Bypass.