bariatric vitamins 4

Are Bariatric Vitamins Best for WLS Patients?

January 13, 2017

Are Bariatric Vitamins Best for WLS Patients?

Bariatric vitamins and vitamin supplementation often causes a lot of confusion after surgery.  There is an entire industry of vitamin manufacturers that focus exclusively on postoperative weight loss surgery patients.  While this industry meets a very important need, it also contains players who sell poor quality vitamins at inflated prices.

Most surgery practices offer bariatric vitamins for sale in their office to simplify the purchasing process. I sell vitamins in my office as a convenience to my patients to prevent them from running to the nearest strip mall vitamin shop where they will likely pay twice as much for lower quality vitamins.  Vitamin sales do not account for a significant profit in our practice, but they do simplify the purchasing process for our patients significantly.

Your vitamin requirements will depend on many factors. How long ago your surgery was performed, which procedure you had, and the types of food that you eat every day all impact your need for vitamin supplementation.

I stress the importance of taking your vitamins every day. Still, I also discuss with my patients how important it is to eat your vitamins every day in the form of vegetables, fruit, nuts, seeds, and beans. Patients who eat large amounts of these nutrient-rich foods will require much less vitamin supplementation than a patient whose diet consists mostly of Lean Cuisine frozen packaged meals and protein shakes.

When making recommendations for vitamin supplementation, I’m always careful to preface any comments with a note about Duodenal Switch (DS) or BilioPancreatic Diversion (BPD) patients. 

Patients who have undergone these procedures require large amounts of vitamins for life, regardless of their baseline diet or length of time from surgery. Many surgeons estimate that the monthly cost of appropriate vitamin supplementation after these procedures is around $200.  A full discussion of Duodenal Switch and Biliopancreatic Diversion vitamin supplementation is beyond the scope of this article and best recommended by a surgeon who performs these surgeries on a regular basis. All of the comments below are intended for patients after either a Sleeve Gastrectomy (VSG) or Gastric Bypass (RNY) procedure.


Immediately after surgery, a bariatric multivitamin is essential.  Bariatric specific multivitamins contain at least 200% of the recommended daily allowance (RDA) of the essential vitamins and minerals.

While many people believe that Sleeve Gastrectomy patients do not require vitamin supplementation, this is not correct. While vitamin deficiencies are less common in Sleeve Gastrectomy patients, they still can occur. Sleeve patients experience a more rapid transit of food through the intestine, decreasing the absorption of vitamins and minerals.

Chewable Vitamins & Nausea

Bariatric multivitamins exist in either chewable or capsule forms. Many patients find the artificial flavors of chewable vitamins difficult to take after surgery, and it is very common for chewable vitamins to induce nausea.  Some brands cause more nausea than others, so sampling several different brands or flavors can often make the difference between being able to take your vitamins or not.

Often, patients tell me that they had no problems with their vitamins preoperatively, but found them intolerable after surgery. This is likely due to the change in your taste for food that occurs after surgery.  Often, artificially flavored and sweetened foods taste terrible after surgery when they were tolerable or even pleasant-tasting before surgery.

Capsule Vitamins & Pill Size

Bariatric multivitamins in capsule form are often concerning to patients who were told to avoid pills above a certain size. However, the capsules on these vitamins are designed to dissolve rapidly, allowing them to be swallowed and absorbed within a few days of surgery. 

Despite this design intention, I’ve found that many patients cannot tolerate these capsules until a few months after surgery.  Again, sampling several different brands and formulations after your surgery can be helpful in finding the best way for you to take your vitamins.

Hierarchy of Nutritional Priorities After Surgery

When patients struggle with taking vitamins after surgery, I am quick to remind them of the hierarchy of nutritional priorities after surgery.  Water and fluids are most important, followed by protein and calorie intake and, finally, vitamin consumption. If you are unable to tolerate any fluids, you will require medical support within one to two days.

If you are unable to consume enough protein or calories, you will require medical support within four to six weeks. If you are unable to take in an appropriate amount of vitamins, you will require medical treatment in approximately four to six months. The urgency for vitamin consumption is much less than it is for fluids, protein, or calorie consumption. 

I urge patients not to allow their efforts to take their vitamins to interfere with their protein or fluid consumption.  You should prioritize vitamins only after you are comfortable keeping down enough fluid and protein.

Multivitamins, Daily for the Rest of Their Life

Many patients stop taking a bariatric multivitamin a few years after surgery. While I officially recommend that all postoperative patients take a bariatric multivitamin daily for the rest of their life, I understand this decision. I think that it is unlikely to cause a problem in the vast majority of postoperative patients, as long as they are eating a diet rich in vitamins and minerals. Within the first few years after surgery, your intestines have not fully adapted to your surgery, and there is some vitamin malabsorption, making supplementation critical. However, over time, your intestines will adapt, and most nutrients will be absorbed.

As I mentioned above, those patients who continue to focus on low-calorie, low-nutrient foods will require lifelong vitamin supplementation since there is very little in the way of vitamins and minerals in these processed foods. 

However, those patients who eat a diet rich in vegetables, fruit, nuts, seeds, and beans will obtain plenty of nutrition from their diet, making a bariatric specific multivitamin unnecessary.  There is one important exception to this rule that will be discussed next - Iron.


Without question, iron deficiency is the nutritional deficiency that I worry about the most in my patients.  At least once per year, I am contacted by a patient of mine that had surgery several years ago who tells me about a recent hospital admission for severe anemia.  The story typically starts with feeling extremely tired and short of breath.  Their primary care doctor runs a routine blood panel and then calls the patients with the results and instructs them to go immediately to the Emergency Room.  This typically triggers a 3-4 day-long hospital stay that includes blood transfusions, colonoscopies, and multiple specialist consultations.  In the end, the only finding to explain the severe anemia is poor absorption after surgery.  The hospital stay and all of the anxiety that it causes can be easily prevented by undergoing regular blood tests to measure iron levels and supplemented appropriately.

Beyond the life-threatening anemias that result from Iron deficiency, it is also the most common nutritional deficiency that leads to hair loss.  Any patient who is concerned with hair loss after surgery, particularly after gastric bypass, should start an iron supplement as soon after surgery as possible.  Many bariatric multivitamins contain Iron, and those concerned about hair loss should opt for these formulations or take an additional Iron supplement starting immediately after surgery.

All weight loss surgery patients are at risk for iron deficiency.

Most dietary iron is absorbed in the first portion of the intestine.  In Gastric Bypass patients, this segment is bypassed, so any iron in our food or supplements won’t be absorbed.  In Sleeve Gastrectomy patients, your smaller stomach results in a shorter transit time through the stomach and first segment of intestine, giving your intestine less time to absorb any iron you ingest.

Approximately 25% of gastric bypass patients and 10% of Sleeve Gastrectomy patients will experience iron deficiency that requires supplementation.  Because most ordinary Iron supplements are absorbed in the first portion of the intestine, it is critical that you take a Bariatric specific iron supplement, rather than just running to the drug store and buying Iron.  Bariatric specific iron supplements contain Iron in a form that can be absorbed throughout the entire intestine.  Typically, these vitamins cost between $10-$30 per month, depending on the brand and the amount of iron that you need to take.  Most drug store iron causes constipation, while bariatric iron supplements rarely do.

I recommend that every postoperative weight loss surgery patient has blood work at least once per year to evaluate your iron levels, for the rest of their life.  Often, iron deficiency does not cause symptoms until five or more years after surgery, so continuing to check every year is critical.  If your iron levels are repeatedly low, I recommend checking every six months until they return to normal.

Patients who stay on top of their iron levels and supplement appropriately are able to view their iron deficiency as a minor inconvenience.  Patients who ignore it entirely run the risk of spending a few days in the hospital being poked, prodded, and interrogated to treat an entirely preventable problem.

Vitamin D

Vitamin D deficiency has reached epidemic levels in our country, we think.  When nearly every blood test I send off reports a low Vitamin D level, I begin to wonder whether we have a clinical problem, or are over-diagnosing something that isn't a concern.  Vitamin D is involved in bone formation, and a deficiency can lead to bone loss, fracture, and osteopenia.  There are also reports linking Vitamin D deficiency to many other problems like depression, fatigue, generalized pain, and weakness. However, skepticism abounds on these more vague effects.

When I find a patient who has a Vitamin D level that is a little low, I encourage sunlight exposure and not much else and reserve treatment for values that are well less than normal (typically <15 ng/mL).  Vitamin D is absorbed only after it dissolves in the fat that we consume in our diet.  Because a gastric bypass procedure reduces your fat absorption, it often requires larger doses of vitamin D for supplementation. I typically recommend 5000 Units daily for patients with a Vitamin D level <15ng/mL and will prescribe an additional 50,000 Units weekly if a patient fails to respond to 5,000 Units daily.

While profound Vitamin D deficiency can lead to devastating problems, it is rare in the 21st century to see significant issues.  For those patients who are diagnosed with a low Vitamin D level, I recommend they supplement appropriately, but don’t worry too much; it’s unlikely that your low vitamin D level will ever impact your health significantly - make sure you continue to stay on top of your iron level.


Calcium supplementation is recommended by our national society for bariatric surgery, the ASMBS.  Despite this, I do not routinely recommend that my patients supplement their Calcium.  There have been a few isolated reports that show a relationship between Calcium supplementation and sudden cardiac death.  Calcium plays a critical role in the maintenance of a stable heart rhythm, and it is possible that taking too much Calcium could disturb your normal heart rhythm.  There are also reports of substantial bone loss after Weight Loss Surgery, but little evidence that I know of that demonstrates that taking a Calcium supplement reduces this risk

There are lots of foods that contain Calcium that do not pose a risk for heart rhythm disorders.  Most people think about dairy products as the best way to get more Calcium in your diet.  Although dairy products do contain lots of Calcium, they are also high in animal fat and protein.  Consuming animal fat and protein results in your urine turning alkaline (the opposite of acidic).  Alkaline urine results in an increase in your Calcium excretion.  While you may be consuming lots of calcium in a glass of milk or piece of cheese, these foods will also cause you to excrete more Calcium in your urine.  The net result is a lot less available Calcium than you thought dairy products provide.

A better option for calcium supplementation is through vegetables and other plant based foods that contain lots of Calcium.  Kale, watercress, Bok Choy and almonds.  These foods contain lots of Calcium and won’t alkalinize your urine and increase the excretion.

Kale contains almost as much Calcium as a glass of milk.  I recommend that those patients who are concerned about bone loss after Weight Loss Surgery drink one large, a green smoothie made with at least a cup of Kale every day.

B Complex

There are eight different B vitamins, and each one plays a critical role in our health.  A B complex vitamin contains most or all of these B vitamins in a single pill.  Most of the B vitamins also have another name.  For instance, Thiamine is vitamin B1, Folate is vitamin B9, and Biotin is vitamin B7.  You can also purchase supplements for each individual B vitamin, but this is rarely necessary except for Biotin.

A bariatric multivitamin contains large amounts of B vitamins, so supplementation with a B Complex is rarely necessary.  However, from time to time, I will see a patient who is not able to tolerate any bariatric vitamins because of their taste or cost.  While taking a bariatric vitamin is ideal, if it can’t be done, it can’t be done.  Instead, I recommend these patients take two ordinary chewable adult multivitamins daily also take 1-2 B complex vitamins daily.

I also typically supplement any B vitamin deficiency with a B Complex vitamin, rather than just supplementing the one that is deficient.  I’ve found compliance with B Complex supplements to be much higher than when patients have to search for an individual thiamine or folate supplement.

Many patients are concerned about their B12 vitamin levels and purchase nasal sprays, patches, or even get injections from their primary care doctor.  This is almost never necessary.  In those patients who take their Bariatric Multivitamin, B vitamin deficiencies are rare.  Occasionally, I will see a patient who has not been taking their vitamins who develops a B vitamin deficiency as a result.  These patients will also benefit from a B complex in addition to starting on a Bariatric Multivitamin.


Biotin is Vitamin B7 and is contained in most B complex formulations, but it deserves special mention because it can help reduce hair loss after surgery.  I encourage patients in their first year after surgery to supplement with large doses of Biotin.  I recommend 10 mg daily (sometimes Biotin is listed in micrograms, so this would convert to 10,000 micrograms daily).  While Biotin does not prevent hair loss altogether, it can reduce it significantly and speed hair regrowth when it starts toward the end of the first year after surgery.

Eat Your Vitamins

A lot of attention is paid to Bariatric vitamin supplements, so many patients mistakenly assume that as long as they take their supplements, they will not suffer any issues related to nutrition.  A bariatric vitamin contains 20-40 different vitamins and minerals, but there are thousands of critical compounds found in food that are necessary to maintain good health. These compounds are often referred to as phytonutrients since they are found predominantly in plants.

Rather than focusing on taking a vitamin supplement, I encourage my patients to eat their vitamins by consuming foods that are rich in phytonutrients.  This can be accomplished by eating lots of fruit, vegetables, nuts, seeds, and beans.

Taking vitamin supplements does not reduce your need to focus on these foods.  Remember that good health cannot be found in a shake, pill or bottle and ultimately comes from eating natural, unprocessed foods.

Dr. Matthew Weiner from Michigan Weight Management Institute

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Dr. Matthew Weiner is a Bariatric Surgeon and the Medical Director of the Michigan Weight Management Institute in the suburbs of Detroit, MI. He has been practicing laparoscopic and bariatric surgery since 2006. Dr. Weiner offers both surgical and non-surgical treatment for obesity in his practice and is available for Skype consults for those patients who live outside of Michigan. In addition to Dr. Weiner's "A Pound of Cure" book, his new book "How Weight Loss Surgery Really Works and How to Make it Work For You" will be available in 2017.