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Tag: nutrition

Covid 19:Anesthesia, Weight Loss Surgery and Malnutrition

October 30, 2021 8:52 am

As the COVID-19 pandemic is charting its course into 2022,  as health care providers, we have had to adapt and adjust to the transient and shifting environment. Testing for COVID-19 has been in place, and is now part of the standard for preoperative work-up. In addition, covid testing will likely be part of screening any surgical procedure for the foreseeable future.

The challenge of pandemic control is the large pockets of populations in the US and worldwide that do not have protection against the virus and are not vaccinated. Vaccination provides the only proven long-term protection against COVID-19 infection and its long-term persistent health effect. In addition, the complication rate reported in scientific journals is negligible compared to the complication and death rate from the COVID-19 infection.

There are implications of covid infection and general anesthesia published in peer-reviewed journals. The increased risk of general anesthesia after covid infection is related to the severity of the initial infection and the extent of the treatment required, and the persistence of the post covid symptoms, including shortness of breath, fatigue, and laboratory finding elevated inflammatory markers. Long after resolution of the acute COVID-19 symptoms, the most common persistent complaints are fatigue, shortness of breath, Joint and chest pain; and all these increase the risk of post-operative complications (Carfì et al., 2020)

The required delay for surgery may be as short as 2-4 weeks to as long as six months or longer if the persistent symptoms are present. Surgery may not be avoidable in a critical life-threatening situation and may be necessary even with a much-increased risk of complication (Collaborative, 2020). Recovery post-COVID-19 may not be complete with the resolution of the initial symptoms (Dexter et al., 2020)

Recent publications and scientific presentations have also shown the protection that weight loss surgery and maintained weight loss provide in those who come down with the COVID-19 infection (Aminian et al., 2021). However, the rate of weight gain, lack of weight loss is worse for weight loss surgical patients post COVID-19 disorder (Bullard et al., 2021; Conceição et al., 2021). Furthermore, patients with COVID-19 infection post weight loss are at a higher risk of malnutrition (di Filippo et al., 2021; Kikutani et al., 2021). Up to 40% of patients have malnutrition if hospitalized with COVID (Anker et al., 2021).

To summarize, Weight loss and weight loss surgery reduce the severity of the initial COVID-19 infection. However, it increases malnutrition risk, requiring nutritional support and surgical interventions in non-responsive cases.



Aminian, A., Fathalizadeh, A., Tu, C., Butsch, W. S., Pantalone, K. M., Griebeler, M. L., Kashyap, S. R., Rosenthal, R. J., Burguera, B., & Nissen, S. E. (2021). Association of prior metabolic and bariatric surgery with severity of coronavirus disease 2019 (COVID-19) in patients with obesity. Surgery for Obesity and Related Diseases, 17(1). https://doi.org/10.1016/j.soard.2020.10.026

Anker, M. S., Landmesser, U., von Haehling, S., Butler, J., Coats, A. J. S., & Anker, S. D. (2021). Weight loss, malnutrition, and cachexia in COVID-19: facts and numbers. In Journal of Cachexia, Sarcopenia and Muscle (Vol. 12, Issue 1). https://doi.org/10.1002/jcsm.12674

Bullard, T., Medcalf, A., Rethorst, C., & Foster, G. D. (2021). Impact of the COVID-19 pandemic on initial weight loss in a digital weight management program: A natural experiment. Obesity, 29(9). https://doi.org/10.1002/oby.23233

Carfì, A., Bernabei, R., Landi, F., & Group, for the G. A. C.-19 P.-A. C. S. (2020). Persistent Symptoms in Patients After Acute COVID-19. JAMA, 324(6), 603–605. https://doi.org/10.1001/jama.2020.12603

Collaborative, Covids. (2020). Delaying surgery for patients with a previous SARS-CoV-2 infection. British Journal of Surgery, 107(12), e601–e602. https://doi.org/10.1002/bjs.12050

Conceição, E., de Lourdes, M., Ramalho, S., Félix, S., Pinto-Bastos, A., & Vaz, A. R. (2021). Eating behaviors and weight outcomes in bariatric surgery patients amidst COVID-19. Surgery for Obesity and Related Diseases, 17(6).

Dexter, F., Elhakim, M., Loftus, R. W., Seering, M. S., & Epstein, R. H. (2020). Strategies for daily operating room management of ambulatory surgery centers following resolution of the acute phase of the COVID-19 pandemic. Journal of Clinical Anesthesia, 64. https://doi.org/10.1016/j.jclinane.2020.109854

Di Filippo, L., De Lorenzo, R., D’Amico, M., Sofia, V., Roveri, L., Mele, R., Saibene, A., Rovere-Querini, P., & Conte, C. (2021). COVID-19 is associated with clinically significant weight loss and risk of malnutrition, independent of hospitalisation: A post-hoc analysis of a prospective cohort study. Clinical Nutrition, 40(4). https://doi.org/10.1016/j.clnu.2020.10.043

Kikutani, T., Ichikawa, Y., Kitazume, E., Mizukoshi, A., Tohara, T., Takahashi, N., Tamura, F., Matsutani, M., Onishi, J., & Makino, E. (2021). COVID-19 infection-related weight loss decreases eating/swallowing function in schizophrenic patients. Nutrients, 13(4). https://doi.org/10.3390/nu13041113

Medication Accumulation in Gut Bacteria May Curb Drug Effectiveness, Alter Gut Microbiome

October 05, 2021 2:06 pm

NEW YORK (Reuters Health) – Many common medications such as antidepressants, diabetes and asthma drugs can accumulate in gut bacteria, altering bacterial function and potentially reducing drug effectiveness, researchers say. “It was surprising that the majority of the new interactions we saw between bacteria and drugs were the drugs accumulating in the bacteria, because up until now biotransformation (chemical modification) was thought to be the only way that bacteria affect drug availability,” Dr. Kiran Patil of the MRC Toxicology Unit, University of Cambridge, told Reuters Health by email. “We also were surprised to see the stark effect of bioaccumulation on bacterial metabolism and on community composition.” “There will likely be very strong differences between individuals, depending on the composition of their gut microbiota,” he noted. “We saw differences even between different strains of the same species of bacteria.” As reported in Nature, Dr. Patil and colleagues grew 25 common strains of gut bacteria and investigated their interactions with 15 structurally diverse oral drugs. The team identified 70 bacteria-drug interactions, 29 of which had not been previously reported. Seventeen of the newly discovered interactions could be ascribed to bioaccumulation – i.e., bacteria storing the drug intracellularly without chemically modifying it, and in most cases without bacterial growth being affected. To gain additional insight, the team investigated the molecular basis of bioaccumulation of the antidepressant duloxetine. They found that duloxetine binds to several metabolic enzymes and changes the metabolite secretion of the affected bacteria. When tested in a microbial community of drug accumulators and non-accumulators, duloxetine markedly altered the small molecules produced by the drug-accumulating bacteria, which the non-accumulators fed on; this caused an overabundance of consuming bacteria, thereby unbalancing the composition of the community. Further, the team validated their findings in C. elegans; worms grown in bacteria that accumulated duloxetine behaved differently from those grown in bacteria that did not accumulate duloxetine. Summing up, the authors state, “Together, our results show that bioaccumulation by gut bacteria may be a common mechanism that alters drug availability and bacterial metabolism, with implications for microbiota composition, pharmacokinetics, side effects and drug responses, probably in an individual manner.” Dr. Patil added, “Next steps will be to take forward this basic molecular research and investigate how an individual’s gut bacteria tie in with differing individual responses to drugs such as antidepressants – differences in response, drug dose needed, and side effects like weight gain.” “If we can characterize how people respond depending on the composition of their microbiome, then drug treatments could be individualized,” he said. “The clinical relevance will hopefully be clear in the next 2-3 years.” Dr. Libusha Kelly of Albert Einstein College of Medicine in New York City commented on the study in an email to Reuters Health, “This work highlights the broad importance of microbe/drug interactions in drug bioavailability and the unrecognized potential for bioaccumulation of drugs to modify metabolite secretion in microbial communities.” “As the authors note,” she said, “this study in bacterial isolates is only the first step towards understanding how bioaccumulation might influence drug metabolism and microbial community composition in the context of the far more complicated communities of microbes in the human body.”
“There are likely additional, cryptic, ways in which bacteria alter bioavailability and drug metabolism in the human body,” she said. “Furthermore, we do not understand how microbiome/drug interactions influence drug efficacy and safety in individual patients, which limits the clinical utility of our field currently. However, the authors uncover an exciting direction for future research.” Source: https://go.nature.com/3CxioHd Nature, online September 8, 2021. Reuters Health Information © 2021

Over the Coubnter Vitmain D3 better than the Prescription Vitamin D2

August 30, 2021 10:41 am

Vitamin D absorption is based on a complex series of pathways in the human body. We have discussed the significance of Vitamin D in a broad health condition, including Covid-19, immune system and bone structures. These articles explain the differences in detail. https://www.dssurgery.com/wp-content/uploads/2021/08/jcem5387.pdf https://www.dssurgery.com/wp-content/uploads/2021/08/jcemE447.pdf We have no finaicial insterst in the recommendations made on our site.

Fat Soluble Vitamins

April 26, 2020 10:20 am

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

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

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. 

pastedGraphic_1.pngFigure 2: Chemical structure of Vitamin D molecule

Vitamin E

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.

pastedGraphic_2.pngFigure 3: Chemical structure of Vitamin E molecule

Vitamin K

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

Night blindness 

Dryness of the eye

Vitamin D Softening and weakening of the bones

Decreased bone formation 

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

Vision problems

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

Arterial calcification




  1. Office of Dietary Supplements – Vitamin A. NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/#. Accessed April 26, 2020.
  1. Office of Dietary Supplements – Vitamin D. NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/VitaminD-Consumer/. Accessed April 26, 2020.
  1. Office of Dietary Supplements – Vitamin E. NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/VitaminE-Consumer/. Accessed April 26, 2020.
  1. Vitamin K. The Nutrition Source. https://www.hsph.harvard.edu/nutritionsource/vitamin-k/. Published July 2, 2019. Accessed April 26, 2020.
  1. 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.

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.