Lab Work after Bariatric Surgery

Steph Wagner

August 16, 2019

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What lab work is needed after bariatric surgery?


what lab work needs to be ordered after bariatric surgery

If your primary care physician is following you after weight loss surgery, read this


Why yearly visits after weight loss surgery?

You may have had this conversation with your bariatric team when your journey began. They recommend coming back once a year for a visit including getting lab work after bariatric surgery.

When life gets going it can start to feel like this appointment is not that important. Maybe you are doing fine and feel you don’t need to go. More commonly, you’ve slipped into old habits and weight is up a little and you are too embarrassed to go back.

What is the point of the annual visit? Is it to get a report card from the principal that you are passing or failing?

The truth is this visit is far more important than the scale they have you stand on in the first 5 minutes. In fact, if it were up to me we would do the weigh in last at the appointment! 

The key to these visits is prevention for any other long-term effects from surgery. Specific labs are measured and compared to the year before so providers can look for trends going up or down. It is far easier to intervene with a vitamin level that is slowly trending down rather than waiting for a deficiency to occur.

labs need to be monitored after weight loss surgery "labs are measured to watch trends going up or down"

There are also symptoms to review and possibly physical exams surgeons may need to perform to make sure no GI issues are coming up. Yes, they do want to know how your lifestyle changes are going and if you are happy with your weight but it really IS more than a report card! In fact, a good team will cheer you on and encourage you towards improvement with a great understanding that this journey is not easy. 

What labs need to be checked?

Data suggests that nutrition deficiencies increase over time AND less patients are getting their lab work after bariatric surgery over time. For that reason, I urge you to return to your surgeon once a year or talk to your PCP about drawing the labs discussed below.

The American Society of Metabolic and Bariatric Surgery (ASMBS) provides a list of what labs need to be checked before and after bariatric surgery.

Please note, if your PCP will be doing your annual labs consider bringing this list to your appointment to have in your file.

What symptoms to look for

As a weight loss surgery patient there are certain symptoms to pay attention to and notify your bariatric team if you experience them. It may be nothing, however, symptoms are an opportunity to rule out anything more serious.

This is another great reason to kept connected to your bariatric program. Sometimes life circumstances keep you from having a bariatric surgeon to contact should you need but even if you are out of town from your surgeon, keep their contact information for your primary care physican to utilize if needed.

I’m going to specifically cover nutrition related symptoms as that is my area of expertise. Of course if you feel any abdominal pain or unusual cramping you should call your bariatric medical team.

signs and symptoms of vitamin deficiencies after bariatric surgery



Vitamin D: Depression, muscle pain, involuntary muscle movements, osteoporosis

Calcium: low bone density, osteoporosis, muscle contractions, spasms, pain

Magnesium: muscle contractions, pain, spasms, osteoporosis


Iron: fatigue, low productivity, spoons shaped nails (or ridges), glossitis (swollen tongue)

B12: numbness/tingling in fingers and toes, glossitis (swollen tongue), fatigue, depression, dementia, gait ataxia (abnormal, uncoordinated movements)

Folic Acid: palpitations, fatigue, Neural Tube Defects, changes in skin pigmentation

Zinc: skin lesions, poor wound healing, hair loss, taste changes

Copper: unsteady gait, tingling, poor wound healing, paralysis

Fat Soluble vitamins

Vitamin A: loss of nocturnal vision, itching and dry hair, xerophthalmia (abnormal dryness of the eye), decreasing immunity, poor wound healing

Vitamin K: easy brusing

Vitamin E: hyporeflexia/weakness, gat ataxia (abnormal, uncoordinated movements)


Thiamin (B1): ‘Dry Beriberi’ (convulsions, muscle weakness, pain of lower/upper extremities, brisk tendon reflexes), ‘Wet Beriberi’ (tachycardia or brachycardia, lactic acidosis, dyspnea), Wernicke Encephalopathy (confusion, hallucinations, psychosis)

*Reference: Stein J, Stier C, Raab H, Weiner R. Review article: The nutritional and pharmacological consequences of obesity surgery. Aliment Pharmacol Ther 2014; 40:582-609

What vitamins do post-ops need?

I created a video and blog post about what vitamins bariatric patients need and how long they will need them after surgery (spoiler alert, it’s a long time!) You can read that article here. 

In summary

Once a year visits may not be fun and they may not be convenient. However, this quick check-in visit may prevent you from much more serious life interruptions! While is it typically best to continue care with a bariatric surgeon, if the only viable option is to use your PCP as your care provider make sure they have the information on what labs to monitor and ask if they have a bariatric surgeon they can refer to if the need ever comes up.

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2 thoughts on “Lab Work after Bariatric Surgery”

  1. Great post. I had gastric sleeve surgery on Oct 31, 2019. Nearing the six month mark and already 100+ pounds gone. As I go through this process , I have become so much more aware of my body’s nutrition and vitamin needs and wouldn’t dare dream of not regularly taking vitamins or scheduling the required regular check ups. And based on this post I have noticed some things that I need to ask my bariatric surgeon about. Thanks again!

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