Written By: Maria Vardapetyan, Eric Baghdasaryan, Osheen Abnous
Vitamins are chemicals that facilitate many processes in the human body such as blood clot formation, good vision, fight infections etc. There are two classes of vitamins. Water soluble vitamins and fat soluble vitamins. Water soluble vitamins dissolve in water. This makes it possible for them to be absorbed through all mucous membranes. Fat soluble vitamins on the other hand do not dissolve or pass through mucous membranes. Fat-soluble vitamins are absorbed in the intestine along with fats in the diet. These vitamins have the ability to be stored in the fat tissues of the human body. Water-soluble vitamins are not stored in the body and have to be taken in daily with the food and dietary supplements. Solubility of a vitamin is not a function of its physical state. There are fat soluble vitamins that have a liquid form and almost all of the water soluble vitamins come in form of pills or powders.
In this article, we are going to focus on fat soluble vitamins. They are all complex molecules made of carbon, hydrogen, and oxygen in different arrangements (see figures 1, 2, 3 and 4). These fat soluble vitamins are vitamin A, D, E and K.
Vitamin A has a major role in vision, immune function, cell growth, and maintenance of organs such as heart, kidneys, lungs, etc. It plays a pivotal role in the health of our eyes, specifically the retina1. Rhodopsin protein, a major protein that has the leading role in the process of vision, is found in the retina where it allows us to perceive light. This protein requires vitamin A to function properly. Without vitamin A, rhodopsin cannot sense light and thus cannot initiate the process by which vision occurs.
Figure 1: Chemical structure of Vitamin A molecule
Vitamin D regulates different chemical reactions that are associated with bones, muscles, and the immune system. The simplified way it does this regulation is it helps absorb calcium from dietary nutrients which in turn strengthens the bones, helps neurons exchange signals to move muscles and helps the immune system to fight against viruses and bacteria2.
Figure 2: Chemical structure of Vitamin D molecule
Vitamin E acts as an antioxidant. Antioxidants are naturally occurring chemicals that neutralize toxic byproducts of many chemical reactions in the human body. When food is consumed and digested, the human body converts it into energy. As a result of metabolism free radicals (toxic byproducts) are formed and are neutralized with the help of vitamin E. In addition, free radicals are also in the environment. Furthermore, vitamin E stimulates the immune system to fight against bacteria and viruses3.
Figure 3: Chemical structure of Vitamin E molecule
Vitamin K can be obtained from food and dietary supplements. There are two forms of vitamin K: phylloquinone (Vitamin K1), which is found in spinach, kale and other greens and menaquinone-4 (Vitamin K2), which is found in animal products. Vitamin K1 is involved in blood clotting, and Vitamin K2 is involved in bone tissue building. Vitamin K1 is the main Vitamin K in human diet (75-90% of all vitamin K consumed), however, it is poorly absorbed in the body4,5.
Figure 4: Chemical structures of Vitamin K1 and K2 molecules
Absorption of fat soluble vitamins
Polarity describes the inherent charge(positive or negative) or lack of charge for any given substance or molecule. Molecules that are charged are referred to as “polar”, while those that lack charge are “nonpolar”. When discussing solubility, it is important to remember the phrase “like dissolves like”. That means polar (charged) substances like to interact with a polar environment like water, since water contains a slight negative charge. Hence, charged substances are water-soluble. Nonpolar substances on the other hand readily interact with nonpolar environments such as fat, which contains no charge. Therefore, molecules that lack a charge such as vitamins A, D, E, and K are referred to as fat soluble.
Due to their water fearing nature, these fat soluble vitamins cannot simply be absorbed directly into the bloodstream (which is mostly water) like the sugars and amino acids in our diet. As their name suggests, these fat soluble vitamins like to be embedded in fatty droplets, which facilitate their absorption in the following way. Fat soluble vitamins group together with other fat molecules to form fatty droplets, effectively reducing the amount of interaction with the watery environment of the intestines. Therefore, without an adequate amount of fat in your diet, your body is unable to effectively absorb these fat-soluble vitamins. This may be true in an intact anatomy, however, post weight loss surgical patients can not increase their fat soluble vitamin levels by increasing their fat intake. This is due to the fact that a high fat diet causes excessive bowel movement which in turn washes away any vitamins taken by mouth. DS limits fat absorption (thus the great weight loss) which can cause vitamin A and D deficiency that can not be easily corrected with oral supplementation.
As mentioned before, fat soluble vitamins are hydrophobic and nonpolar, which means they are also fat loving or lipophilic. Excess fat soluble vitamins can be stored in the liver and fat tissue. Therefore, these vitamins do not need to be eaten every single day since stores of these vitamins can sustain a person for some time. It may take several weeks or months for our body to deplete these stores of fat soluble vitamins which is why it generally takes a longer amount of time for fat soluble vitamin deficiencies to manifest themselves. The ability to store these fat soluble vitamins in tissues can also lead to vitamin toxicity – marked by an excess of vitamin stores in our body.
Clinical manifestations of A, D, E, K deficiency
|Vitamin||Clinical Deficiency manifestations|
|Vitamin A||Vision Problems
Dryness of the eye
|Vitamin D||Softening and weakening of the bones
Bone shape distortion
Bowed legs (generally in children)
|Vitamin E||Damage to red blood cells
Tissue/organ damage due to inability to supply enough blood
Nervous tissue malfunction
|Vitamin K1||Excessive bruising
Increased bleeding time
Small blood clots under nails
Increased bleeding in mucous membrane
|Vitamin K2||Weak bones
Increased plaque deposits along gumline
- Office of Dietary Supplements – Vitamin A. NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/#. Accessed April 26, 2020.
- Office of Dietary Supplements – Vitamin D. NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/VitaminD-Consumer/. Accessed April 26, 2020.
- Office of Dietary Supplements – Vitamin E. NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/VitaminE-Consumer/. Accessed April 26, 2020.
- Vitamin K. The Nutrition Source. https://www.hsph.harvard.edu/nutritionsource/vitamin-k/. Published July 2, 2019. Accessed April 26, 2020.
- Beulens JWJ, Booth SL, van den Heuvel EGHM, Stoecklin E, Baka A, Vermeer C. The role of menaquinones (vitamin K₂) in human health. The British journal of nutrition. https://www.ncbi.nlm.nih.gov/pubmed/23590754. Published October 2013. Accessed April 26, 2020.
The scientific literature is riddled with evidence pointing to the benefit of early metabolic surgery as a superior treatment, remission and possible cure option for diabetes. Unfortunately, the medical education, pharmaceutical companies, primary care healthcare delivery systems and third party payers (health insurance companies) have not caught up with the published data. The American Diabetes Association has changed their guidelines to reflected the benefit for combating diabetes with weight loss surgery.
There is ample evidence of the superior outcome of surgery as a treatment option for diabetes when compared to medical managment. Cummings et.al, in a published article in Diabetes Care, showed sustained stabilization of the Hemoglobin A1C six years after surgery. In contrast, there was no significant changes noted in the non-surgical group.
Jans et.al. , in November of 2019 showed that the patients who had NOT been on Insulin, and had metabolic surgery had the highest long term success for resolution and remission of the diabetes. This identifies that having a patient be proactive in their care by having metabolic surgery improves success rates.
The exact mechanism by which the diabetes is resolved is unclear. The weight loss may play a role. There are numerous hormones and neuroendocrine modulators which control the complex metabolic pathways. Batterham et.al., in Diabetes Care (2016), published a summary overview of the possible mechanism involved in diabetes improvement following metabolic surgery.
There are a number of overlapping and sequential layers for possible reasons why diabetes resolves after weight loss/metabolic surgery. These may be directly related to surgery and the reduction of the calorie intake or absorption. It may also involve the neuroendocrine modulators.
What can be said definitively is that early surgical intervention is best and most likely the only permanent solution to type II diabetic resolution. There is no medical justification in not considering metabolic surgery in diabetic patients who may also have difficulty with meaning a BMI< 35.
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.
It’s important to understand Vitamin D metabolism and deficiency potential following weight loss surgery Vitamins after DS need to be followed via laboratory blood studies. There are basic vitamin needs but individual needs should be based on medical history, genetics, alimentary limb length, common channel length and other surgical and physiologic determinations. Vitamins after DS are a life long commitment as well as protein needs and hydration. Duodenal Switch is a malabsorptive procedure which requires at least yearly laboratory blood studies, daily vitamins/minerals, daily high protein and daily hydration intake. There is not an all in one vitamin that is adequate for a DS patient or tailored to your individual needs. (example: you may need more Vitamin D and less Vitamin A if you are taking a all-in-one vitamin you can’t get more of one and less of another vitamin)
DS patients are recommended to take Dry forms (water miscible form) of Vitamin A, D3, E, K due to the fat malabsorption after DS. Dry formulations by Biotech are processed so they can be absorbed by a water soluble method after the DS procedure. Vitamin D seems to be the vitamin that can become deficient the easiest, followed by Vitamin A. Take these vitamins away from dietary fat.
In some cases, patients may need injectable Vitamin A or D to improve vitamin levels.
Many DS surgeon’s do not recommend Children’s vitamins or chewable vitamins unless there is a specific reason or need for them.
DS Surgeon Blog on Vitamin D:
Webinar on Vitamin D metabolism:
Medications that effect Bone health:
This does not constitute medical advice, diagnosis or prescribing. It is simply a compiled list of gathered information. If you are in doubt or have questions please contact your medical healthcare professional.
“…What is the length of my common channel” is probably one of the frequently asked questions about the duodenal switch operation in the office. This usually comes up at the initial consult when patients repost credible sources such as Dr. Google and Dr. Facebook for patient with different bowel length have done well or not so after duodenal switch operation. Dr. Hess described the Duodenal Switch by using total bowel length measurements and creating the common channel as a percentage of the total small bowel length. However, it seems that this is being done less and less.
This leads to my explanation that is on the website
Hess calculator : Bowel Length Calculator
How the actual measurements matters: Bowel length video link
In 2019, Bekheit et.al published a very interesting study comparing total small bowel length (TSBL) to a number of variables such as height, weight, sex and BMI. They identified a few loose correlations. Male patient have longer TBSL than females. There was correlation between TSBL and height stronger in males than females but not statistically significant.
In Conclusion they reported ” Despite statistical significance of the correlation between the TSBL and the height and weight of the included participants, the correlation seems to have no clinical meaning since the effect size is negligible. ”
As I have previously discussed this Making the common and alimentary length standard for every duodenal switch patient will make some loose too much and other not enough weight.
Figure 1 shows TSBL on the horizontal axis, and height, weight, BMI and Age on the vertical axis. For the most part what they all show is that one can not predict how long a patients bowel is by any of the measures that we take in the office as a part of the routine exam.
This raises, the concerns that I had raised previously. How could two similar patients who have the same weight, age, sex and BMI have the same surgery and expect the same result if one of them has TSBL of 400 cm and the other one 800cm?
If both of the patients get the same “cookie cutter” duodenal switch with the same lengths, then the patient with TSBL of 400 will have much longer common channel if the surgeon does not customize the length of the bowel. This is an example of many patients whom we have revised over the years where they had a duodenal switch done with the “standard” 125cm common channel and when we measured the total length the patient had 500 cm TSBL.
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.
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.
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.
Gastrointestinal (GI) Bleed following weight loss surgery is rare but does require knowledge of the particular bariatric surgical procedure the patients has and how to proceed with diagnostics to fully evaluate the situation. Acute or chronic gastrointestinal bleeding can cause anemia in patients. However, Anemia may also be caused by nutritional deficiencies (iron, vitamin , minerals), Kidney disease, bone marrow disease and others. The work-up for anemia following weight loss surgery follows a routine protocol. If there is an evidence of bleeding from intestine (bloody emesis, bloody bowel movement, “tar” like black bowel movements) then the diagnostic work up would include an upper and lower endoscopy.
Upper endoscopy Esophagogastroduodenoscopy (EGD): evaluates the esophagus, stomach and a limited area of the duodenum past pyloric valve.
Lower endoscopy Colonoscopy or coloscopy: evaluates the rectus and the entire colon.
Between these two tests, there is still a considerable amount of the small bowel that is not accessible or visualized with endoscopic procedures. For the small bowel, examination Capsule endoscopy is an option in an intact GI tract. Patients who have had Gastric bypass RNY or the Duodenal Switch, the large segments of the small bowel can not be visualized or examined with capsule endoscopy.
Patients who have had Duodenal Switch, Gastric Bypass and SADI – S would need a tagged red cell scan or CT angiography if GI bleed is suspected in areas of the small intestine that are inaccessible by endoscopic procedures.