Category: Gastric Bypass
Vitamin D level and Liver Function Test (LFT) elevation
February 08, 2026 11:21 am
After weight-loss surgery, some patients may experience a transient elevation in liver function tests that resolves over time. We have previously reported on this. IT is essential to distinguish between the Duodenal switch and the SIPS/SADI procedure, where some patients are led to believe they are identical. These procedures differ physiologically, and their weight loss and metabolic behaviours vary significantly.
Other than the stress of the weight loss, obesity, and comorbidities of obesity, there may be other anatomical post-surgical causes for elevated liver function test. This has also been discussed extensively.
A recent literature review supports the protective effects of vitamin D supplementation.
Elevated liver enzymes may be caused by many factors, including nutritional deficiencies, excessive supplementation (turmeric), medications, alcohol, adhesions causing partial bowel obstruction, and increased enterohepatic bile reabsorption . I would be very cautious about associating vitamin D supplementation with elevated liver function test results, even if the vitamin D level is in the very high normal range, regardless of the daily dose (much less frequent with injectable).
Vitamin D, as a fat-soluble vitamin, however, protects the liver and improves liver function test even in very high serum level . In rare cases, prolonged, elevated vitamin D levels may strain the liver. In Fact, the association of the vitamin D level and liver disease, including cirrhosis, leads to hepatocellular carcinoma (HCC) and dea h. Vitamin D protects the liver from HCC but cannot reduce the risk of cirrhosis.
How does a stapler staple and cut at the same time
February 11, 2025 12:27 pm
The gastrointestinal staplers simultaneously pass six rows of staples and cut in between them to create two secure lines of staples, three rows on each side. The staples come in different thicknesses and lengths for various applications. Staple cartridges that are used for colon surgery are usually thicker tissue staples than those that are used for small bowel stapling.
Different manufacturers have different color coding.
Another question I frequently get asked is, How does a stapler staple and cut at the same time? The stapler needs to be thick enough to not tear through the tissue and provide uniform pressure for control of bleeding and prevent leaks. It can not be too large either.
When stapling on the stomach for sleeve gastrectomy, the stomach wall thickness is different. We use different-sized staples to accommodate the thicker part of the lower stomach toward the thinner part of the stomach where it meets the esophagus.

Video of stapler demonstration
Zoom Group Meeting
September 21, 2020 7:10 am
We are excited to announce we will be having a Zoom group meeting Tuesday, September 22, 2020 at 7:00 PM PST. We hope to see you online!
Registration is required. Please follow the link to the meeting registration.
Medication Absorption After Weight Loss Surgery
March 30, 2020 8:01 am
Weight loss surgical procedures, in one form or another, achieve the desired effect of weight loss by altering absorption of fat, protein, and carbohydrates. This results in decreased total absorption of required calories.
An unintended consequence is the altered absorption of medications. Frequently I am asked about the specific medication. Usually the answer is vague since the information is limited on specific medications. If the desired effect is not achieved, then it is probably not being absorbed well. Specially, if the same dose of the same medication working well before surgery.
There is a summary article about the Theoretical absorption pattern of different weight loss surgical procedures.
Articles
March 22, 2020 6:57 pm
Stapled Anastomosis
December 30, 2019 11:23 am
As I was looking over old archives, I came across the following pictures that were taken years ago. These were photographs taken to demonstrate the technique for the construction of the anastomosis of the biliopancreatic channel and alimentary channel of the Duodenal Switch.
The steps of doing the stapled anastomosis of the Duodenal Switch is generally unchanged during the laparoscopic approach to the procedure.

The stitches are placed to secure the bowel together. Two small openings are made in each limb of the bowel to be stapled together (the biliopancreatic limb on the bottom and the alimentary on the top of the image).
It is important to also align the bowel in the same peristalsis direction. This means that the contraction and the relaxation motion of the bowel should all point in the same direction. This should reduce the risk of complications such as intussusception.

When the stapler is fired in opposite direction, a very wide anastomosis is created.

Once the anastomosis is created, then the last staple is used to close the opening that was made. This staple line is perpendicular to the direction of the anastomosis to avoid making the opening narrow.
We originally published this technique in 2003 on Obesity Surgery Journal.
Copper Deficiency Intravenous SupplementationExclusive Member Content
November 17, 2019 9:23 pm
Sunscreen
June 27, 2019 3:03 am
Recently there has been some research and concern regarding sunscreen and the chemicals within them. This has led to findings that can be concerning but that need further research.
Post weight loss surgical patients, and in general patients who suffer with obesity, before or after weight loss surgery, have low vitamin D level. This may be caused by a number of factors. One such factor may be the reluctance to get skin exposed to sunlight in order for the bodies natural Vitamin D pathways functioning.
The recommendations are for daily exposure to sun. This not only is critical to the vitamin D metabolic pathways, but also help with bone health, immune function, mood, counteracting depression.
In a recently published online article, concerns were raised that some of the ingredients of some of few sunscreens are absorbed in the blood stream. This is a small study, and as the results indicates, it is not recommending to stop using the sun screens. Be aware of your sun exposure, timing exposure, and the ingredients in your sunscreen.
You can find past blog posts on Vitamin D, Bone health, etc here
Thyroid Medication Absorption And Weight Loss Surgery
June 10, 2019 8:59 am
Question : “Do I have to take higher dose of thyroid medication after the duodenal switch? ”
Answer : “Maybe”
With all weight loss surgical procedures, there may be changes to absorption of medications. It is easily understood why duodenal switch may results in decreased absorption of fat-soluble medication. What is not as clear is the reduction in absorption of other medication with procedures that do not explicitly change the absorption at the level of the small bowel directly.
The research data is all over on this topic. There is published literature that shows improvement in the thyroid function after gastric bypass and the sleeve gastrectomy. However, the exact mechanism is not completely understood.
There is research that reports “…decreased postoperative levothyroxine requirements.” Other have shows no correlation between the length of the bowel distal to duodenum to absorption of thyroid medication.
With all this confusing data, the best course would be to always “treat the patient and not the lab results.”
If a patients who has been on medications with stable number and symptoms, suddenly presents with complaints of hypothyroidism after weight loss surgery, it’s possible the medications should be up adjusted even if the thyroid lab values may not be as defining.
Osteoporosis Medications, Action and Side Effects
May 25, 2019 3:40 pm
Treatment options should be approached is a global and systemic fashion. It is critical that the nutritional status is at its best possible and optimized for important healthy bone vitamins and minerals. Low protein needs to be corrected. Special attention should be given to nutrients, minerals and vitamins. These include Protein, Calcium, Magnesium, Vitamin D, and Vitamin K1/K2to name a few.
Healthy bones require ongoing and routine force in the form of exercise to remain health. Just as exercise improves muscle strength, it also improves bone health. Exercise is also critical in improving bone structure and density. Ideally, exercise should be weight bearing and resistance. Examples include: hiking, walking, jogging, climbing stairs, playing tennis, and dancing. Resistance type exercise is weight lifting and resistance bands. These exercise work by creating a pull or force on the bone either by gravity, movement or weight. Always check with your physician before beginning an exercise routine, start slowly and building up to longer periods of time. The ideal goal would be at least 30 minutes a day, every day, if you are able.
We frequently see patients immediately started on osteoporosis medications without checking or improving some of the nutritional markers noted above or without looking at exercise history. In some case, the medication recommended are contraindicated due to nutritional status.
The medications can be grouped in to those that help with new bone formation (Anabolic agents) or those that help by suppressing the bone breakdown phase (Antiresorptive agents).

National Osteoporosis Foundation has an exhaustive list (below) of medications for treatment of Osteoporosis.
The table below outlines the side effects and mechanism of the actions of the common medications used for treatment of osteoporosis which was published by the University Health News Publication on August of 2014.

With all this information, the few points to remember is that the most important factors in healthy bone structure are the nutritional status Protein, Calcium, Magnesium, Vitamin D, and Vitamin K1 levels.
This is an animation of normal bone Metabolism. It shows how bone structures is taken down and rebuilt continuously. This allows for a healthy bone maintainence as we age. The key is the balance of breakdown (osteoclast) and the build up (osteoblast) activity is regulated. Osteoporosis develops when there is more breakdown that build up. 
With permission of Dr. Susan Ott of University of Washington.
Additional information available on her site.
Past blogs on Bone Health.






