Your Post-Surgery Power 6: Essential Vitamins & Minerals (Part 1)
October 6, 2025Can you just take a Flintstone’s Complete multivitamin and call it a day after bariatric surgery? Or do you really need all those specific vitamins and minerals? And what about timing? Can you take everything at once, or will that backfire?
The right vitamin and mineral supplements aren’t optional; they’re essential. After bariatric surgery, vitamins and minerals become part of your daily, lifelong routine. Think of them as a key part of your success strategy. Not just nice to have, but a must-have. Maybe no one sat you down and explained your supplement needs clearly. You're not alone. A lot of people tell me that they feel confused about what they need to take, when to take it, and why it even matters.
Nutrient Deficiencies Are Common After Bariatric Surgery
The truth is, nutrient deficiencies are common after bariatric surgery, and some types of surgery put you at higher risk than others. For example, procedures like Roux-en-Y gastric bypass and biliopancreatic diversion are more likely to cause long-term nutrient issues than sleeve gastrectomy (LSG) or gastric banding (LAGB).
That’s why it’s a good idea to check with your bariatric dietitian for clarity if you’re unsure about which supplements and how much are needed for your procedure. And recommendations do vary between surgical centers and even professional groups, so don’t be surprised if your supplement suggestions are different from someone else you know who’s had surgery. Remember, your surgery is unique to you.
Keep in mind these three important supplement tips:
- You will typically start supplements when you go home from the hospital, which is usually 2–4 days after surgery if you didn’t start taking them before your surgery.
- Depending on the surgical procedure, your body may change in its ability to absorb vitamins and minerals. Chewable or suckable pills or liquids are a really good idea the first 1-3 months. Ask your dietitian for guidance, as they usually have a protocol. Then, you can switch to capsules or tablets if you desire.
- Routine vitamin and mineral screenings or lab tests should be part of your care from your health care team. How often and what they screen for will vary with your procedure.
A lot has changed in the vitamin-mineral world. In the not-too-distant past, bariatric-specific supplements weren’t as common, so we combined various over-the-counter products to get what we needed. Now, most quality bariatric supplements follow the ASMBS (American Society for Metabolic and Bariatric Surgery) recommended supplement guidelines based on a current review of research for key vitamins and minerals needed after surgery. That’s why some bariatric vitamins are better and easier to take because everything, or almost everything, you need is in one or two supplements per day.
Let’s dig deeper into the supplement suggestions, knowing that your health care team may tweak these. Part 1 covers multivitamin and mineral supplements along with vitamin B-12. In part 2, let’s shine a light on iron, calcium, vitamin D, and thiamine.
Take A “Complete” Multivitamin Plus Mineral Supplement
Take a “complete” multivitamin plus mineral supplement that is bariatric specific. Complete means it contains the typical A-Z formulation of vitamins and minerals similar to what you find in an adult supplement but in amounts specific to bariatric surgery. Do a label check and be sure it is a bariatric supplement and that it contains both vitamins and minerals. Then look for vitamins A, D, E, K, folic acid, and thiamine, along with the minerals iron, zinc, selenium, and copper. If it’s a good quality bariatric supplement, it will contain all of these and more.
Multivitamin-mineral supplements are available both with and without iron. You can choose to take your iron in the multi, and there are multis that contain different amounts of iron. If your multi contains iron, be sure and take your calcium separately. Wait about two hours or more from the time you take the multi, or the calcium will not be absorbed well by your body. You want to be sure you get the amount of iron recommended for you, so check with your bariatric dietitian. Also, the daily number of multi-capsules or tablets will vary based on the brand and what they contain. Typically the dose will be one or two tablets, capsules, or chewables per day.
You Will Likely Need Vitamin B-12
The daily suggested range is 250-1000 micrograms (ug or mcg) a day of Vitamin B-12, which is also called Cobalamin. The dose depends on your surgery, your lab results, and the route of administration…meaning under the tongue, swallowed, etc. On occasion an intramuscular injection of B12 or a nasal spray will be ordered by your health care team. You can take B12 at any time or with any other supplements. Often, your multivitamin-mineral supplement will have adequate B-12, so check the label (Supplement Facts label in the United States) before you buy additional.
Be sure and discuss your lab screenings with your health care team before you decide to take any extra B-12. More does not mean better for your body.
The body’s absorption of B-12 is affected by bariatric surgery due to surgical changes, which can affect acid production and reduce the availability of what’s called the intrinsic factor. This intrinsic factor improves B-12 absorption and use by the body. When the intrinsic factor is insufficient, B-12 doesn’t get absorbed and used as it should. You could experience neurological symptoms, including numbness and tingling of your arms, legs, and skin, plus feel like your coordination is off. This is a prime reason why routine screenings are so important and typically done every six months or so. These screenings help your health care provider pick up on a possible deficiency, hopefully before it becomes a problem.
A bariatric multivitamin-mineral supplement, along with additional B12 when needed, are definitely worth the ongoing investment from a cost standpoint, as they ensure that your body receives the vitamins and minerals that help prevent deficiencies and help your body perform as it should.
Editor's Note: Part 2 of this article will publish 10/8/25
Bariatric dietitian Dr. Susan Mitchell is host of the podcast Bariatric Surgery Success.
 | ABOUT THE AUTHOR Bariatric dietitian Dr. Susan Mitchell is host of the podcast Bariatric Surgery Success. Selected as one of the Best 35 Dietitian Podcasts, Bariatric Surgery Success was chosen from thousands of podcasts on the web ranked by traffic, social media followers, domain authority, and freshness. With a focus on nutrition before and after bariatric surgery, I help you eat for success while you conquer cravings, emotional eating, and weight regain. Read more articles by Susan! |
