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WLS Patients Need Personalized Bariatric Vitamin Regimens

WLS Patients Need Personalized Bariatric Vitamin Regimens

45% of bariatric patients are deficient in iron.

56% of bariatric patients are deficient in folate.

A staggering 60-80% of bariatric patients are deficient in vitamin D.

The list goes on [1]. Weight loss surgery (WLS) patients are no strangers to nutritional challenges - even before they’ve had surgery. Most patients present with some array of deficiencies, and getting the surgery adds another layer of nutritional complexity to post-op life.

And it’s not simply a matter of forcing down a mouthful of pills every day. Excess consumption to the point of toxicity is a real concern. Financial difficulties can make even the most diligent patients fall off the wagon.

Plus, we’re all human: pill forms, flavors, pill counts, and other factors have an undeniable effect on patients’ ability to stay consistent.

Vitamin and mineral supplementation is an unavoidable part of the WLS journey

Regardless of surgery type – whether it is a gastric sleeve, gastric bypass or duodenal switch operation – patients need vitamin and mineral supplementation.

All of these operations impair nutrient absorption to various degrees. This impairment results in weight loss, but also comes with other undesirable effects: namely, reduced vitamin and mineral absorption.

If supplementation is ignored, severe deficiencies may develop. For example, a vitamin A deficiency can cause blindness in severe cases. A vitamin K deficiency can result in bleeding gums and easy bruising. Lack of vitamin B12 might mean anemia, irritability, forgetfulness and dementia. Vitamin D and calcium deficiencies mean osteoporosis, and so on.

The American Society for Metabolic and Bariatric Surgery (ASMBS) has published generalized guidelines for micronutrient supplementation after surgery [1, 2]. These guidelines are exactly that: guidelines for medical professionals. They do not sufficiently represent the medical needs of an individual patient.
In fact, one of the paper’s principal conclusions is that “it is the responsibility of the registered dietitian nutritionist and WLS program to determine individual variations as they relate to patient nutritional care.”

Despite this need to “determine individual variations” - in other words, take personalized regimens - it is all too common to see patients taking a “one size fits all” approach. This usually happens when patients purchase high-dosage “bariatric” branded pills that claim to “meet or exceed ASMBS guidelines.” They then mistakenly believe that fulfilling these baseline guidelines is all that they need.

"One size fits all" is rarely the right approach

A patient who strictly attempts to “meet or exceed the ASMBS guidelines” for the entirety of his or her post-op life by adopting the “one size fits all” approach is making the following assumptions:

  • They are not already deficient (or in excess) of any particular vitamin/mineral, prior to surgery
  • They will never develop deficiencies (or excess) over time
  • Their body will react to surgery in the exact same way as that of another patient

These assumptions are particularly dangerous if a patient does not reassess his or her requirements on a regular basis by getting bloodwork and doing annual follow-up meetings.

Looking solely at the first assumption is a major cause for concern. The reality is that most patients start with different blood levels of vitamins prior to surgery. Many levels might be on the low end of “normal,” and many are outright deficient:

  • 60 to 80% patients are deficient in vitamin D [3, 4]
  • More than 10% of preoperative patients have a B12 deficiency [5]
  • 15-47% are deficient in B1 [6,7]
  • Up to 56% are deficient in folate [8]

All of these differences are mainly due to individual food consumption habits, different levels of exposure to the sun, and other various activities with which people engage daily.

Because the starting point varies for so many patients, it is impossible to consistently address vitamin supplementation needs with a “one size fits all” approach.

Even with regular follow-up, course-correcting “one size fits all” vitamin regimens is challenging

When a patient’s vitamin level drifts down below the normal range - or he/she was, like many patients, deficient to start with - he or she will typically compensate by adding additional vitamin products to their regimen.

After several rounds of this process over the years, it can become impossible - or at least extremely complicated - to add up total dosage levels from all the different brands and products with nontrivial ingredient lists.

Unaware of total intake, a patient is liable to end up with toxic dosages of individual vitamins. The resulting adverse health effects can be almost as bad as deficiencies: too much vitamin A in pregnant women can be teratogenic, too much B6 can result in neuropathy, and so on.

Furthermore, being merely aware of aggregate dosages is still not enough. If the patient takes a one-size-fits-all pill and suddenly his or her blood level of vitamin B12 skyrockets to an excessively high level, most professionals would suggest decreasing the B12 dosage. But how should a patient accomplish this in practice? We cannot simply remove vitamin B12 from the pill.

Patients need to take what’s right for them as individuals

Every individual patient is not like the rest 

Fortunately for everyone: the vitamin products that solve this problem already exist.

If patients browse for vitamin products, they’ll find hundreds of thousands - maybe millions - to choose from.

Each product has some combination of the ingredients that fulfill some percentage of a bariatric patient’s individual requirements. When patients add together Product A + Product B + Product C, they will get exactly what they need as individuals. The possibilities for product combinations are infinite.

When patients look at the entire vitamin market to fulfill their needs, they cease to be tied to specific, bariatric-branded products that “meet or exceed ASMBS guidelines.” After all, the “ASMBS guidelines” those products quote are in fact a range of possibilities, intended only for an average patient who needs only maintenance supplementation.

For some patients who fit that “average” description, a $70/month, pill-minimizing, great flavor option from Bariatric Advantage is the best choice.

Other more financially-conscious patients can find a $20/month, pill-heavy option coming from a combination of brands like Centrum and Kirkland.

Still others can find a balance. Maybe they don’t need any iron or B6, so there’s a good-tasting $40 combination of lesser-known brands that will suit them both financially and medically.

Modern technology can make this process easier

This regimen personalization is certainly possible for a patient to do via manual process: go on Amazon, search around, read Supplement Facts labels, convert units, and compare standardized prices.

But we know that sifting through this mass of commercial product information isn’t an easy task. We’ve built a web application that makes the searching and calculating easy: BariBuilder Shop (

Please note that development is on hold. If you think this is a useful product, shoot us an email with that feedback at - it'd be helpful to know that we should put our focus back into it!

A patient can enter his or her ingredient goals and sit back as the software does all those calculations to surface the best choices for them. By the time they’re doing check-out, they’ll have in front of them a regimen that is both cost-effective and matches their medical needs exactly.


1. Parrott J, Frank L, Rabena R, Craggs-Dino L, Isom KA, Greiman L. American Society for Metabolic and Bariatric Surgery Integrated Health Nutritional Guidelines for the Surgical Weight Loss Patient 2016 Update: Micronutrients. Surg Obes Relat Dis. 2017 May;13(5):727-741. doi: 10.1016/j.soard.2016.12.018.

2. Mechanick JI, Youdim A, Jones DB, Garvey WT, Hurley DL, McMahon MM, Heinberg LJ, Kushner R, Adams TD, Shikora S, Dixon JB, Brethauer S; American Association of Clinical Endocrinologists; Obesity Society; American Society for Metabolic & Bariatric Surgery. Clinical practice guidelines for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient--2013 update: cosponsored by American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery. Obesity (Silver Spring). 2013 Mar;21 Suppl 1:S1-27. doi: 10.1002/oby.20461.

3. Buffington CK, Walker B, Cowan GS, et al. Vitamin D deficiency in the morbidly obese. Obes Surg 1993;3:421– 4.

4. Ybarra J, Sanchez-Hernandez J, Vich I, et al. Unchanged hypovitaminosis D and secondary hyperparathyroidism in morbid obesity after bariatric surgery. Obes Surg 2005;15:330 –5.

5. Madan AK, Orth WS, Tichansky DS, Ternovits CA. Vitamin and trace mineral levels after laparoscopic gastric bypass. Obes Surg 2006;16:603– 6.

6. Carrodeguas L, Kaidar-Person O, Szomstein S, Antozzi P. Preoperative thiamin deficiency in the obese population undergoing laparoscopic bariatric surgery. Surg Obes Relat Dis 2005;1:517–22.

7. Flancbaum L, Belsley S, Drake V, et al. Preoperative nutritional status of patients undergoing Roux-en-Y gastric bypass for morbid obesity. J Gastrointest Surg 2006;10:1033–7.

8. Boylan LM, Sugerman HJ, Driskell JA. Vitamin E, vitamin B-6, vitamin B-12, and folate status of gastric bypass surgery patients. J Am Diet Assoc 1988;88:579 – 85.

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Gintas Antanavicius, MD, FACS, FASMBS


Dr. G is a co-founder of BariBuilder. A US-based expert surgeon with over 10 years of bariatric experience, he regularly publishes research in medical journals like SOARD, Obesity Surgery, etc.

Tadas Antanavicius


Tadas is a co-founder of BariBuilder. A former Goldman Sachs software engineer, Tadas has spent several years working with early-stage technology companies as a product designer and software engineer.