A Systematic Review: Vitamin D Status and Sleeve Gastrectomy. Obes Surg. 2017;27:215-225. [PMID: 27815862 DOI: 10.1007/s11695-016-2436-1]

Gastrointestinal surgery, malabsorptive conditions, and postoperative hypocalcemia after neck surgery

BACKGROUND

Postoperative hypocalcemia is a common complication of thyroid and parathyroid surgery. Patients with prior gastric bypass face increased risk of postoperative hypocalcemia, but the impact of other malabsorptive conditions is not well understood. In this study, we evaluated the relationship between multiple medical and surgical malabsorptive states and hypocalcemia after thyroid and parathyroid surgery.

METHODS

We performed a retrospective cohort study of patients who underwent total thyroidectomy and/or parathyroidectomy in Optum's deidentified Clinformatics Data Mart Database (2004-2022). Patients were categorized as having surgical (foregut/midgut: gastrectomy, intestinal bypass, enterectomy, enterostomy, pancreatectomy, or hindgut: colectomy/colostomy) or medical (Crohn or Celiac disease) malabsorptive conditions. The primary outcomes were early (<7 days) and late (7-365 days) postoperative hypocalcemia. Logistic regression was performed to determine the associations between malabsorptive conditions and outcomes.

RESULTS

Of 25,400 patients (56.9% total thyroidectomy, 40.8% parathyroidectomy, and 2.4% both procedures), 4.0% had a pre-existing malabsorptive condition. Early postoperative hypocalcemia occurred in 8.8% of patients, and late hypocalcemia in 18.3%. Thyroidectomy was associated with a greater likelihood of hypocalcemia than parathyroidectomy (odds ratio: 1.22; P < .001). Pancreatectomy was associated with twice the adjusted odds of postoperative hypocalcemia (odds ratio: 2.27; P = .031) across both procedures. Patients with prior foregut/midgut surgery were at higher risk after total thyroidectomy (odds ratio: 1.65, P = .002). This association was significant in late (odds ratio: 1.82, P < .001) rather than early hypocalcemia (odds ratio: 1.33, P = .175). Hindgut surgery and medical malabsorption did not demonstrate such associations.

CONCLUSION

Prior foregut and midgut resections may predispose patients to postoperative hypocalcemia, particularly in patients undergoing total thyroidectomy.

Effect of Laparoscopic Sleeve Gastrectomy on Calcium Metabolism Parameters, Vitamin D, and Parathyroid Hormone in Morbidly Obese Patients: Short-Term Results

OBJECTIVE

Sleeve gastrectomy (SG) is a widely utilized bariatric surgical procedure. It may affect various aspects of nutritional and metabolic health, including calcium (Ca) metabolism, vitamin D levels, and parathyroid hormone (PTH) secretion. We aimed to investigate the effect of laparoscopic SG (LSG) on Ca metabolism parameters, vitamin D, and PTH in morbidly obese patients.

MATERIALS AND METHODS

This single-center, retrospective cohort study was conducted at the Department of General Surgery, Avrupa Safak Hospital, Istanbul, between March 2021 and November 2023. A total of 78 patients were included in the study. The procedure involved the resection of approximately 80% of the stomach, creating a tubular gastric sleeve. All patients underwent postoperative follow-up at six and 12 months.

RESULTS

Of the 78 patients, 49 (62.8%) were females and 29 (37.1%) were males. The mean age of the patients was 31.2±9.8 years. The mean weight was 126±12.2 kg and the mean BMI was 47±6.9 kg/m2. There was a significant decrease in the BMI values following surgery (p<0.01). Vitamin D level was found to be 18.7±4.2 ng/mL at baseline, which increased to 37.6±2.5 ng/mL at 12 months after surgery (p<0.01). Before surgery, the PTH level was 69.1±8.7 pg/mL, which decreased to 39.3±5.5 pg/mL at 12 months postoperatively (p<0.01). The mean serum Ca level at baseline was 9.2±1.4 mg/dL, which increased to 10.1±0.4 mg/dL at 12 months after operation (p<0.01).

CONCLUSION

Our study results suggest that low vitamin D levels are commonly observed in patients undergoing bariatric surgery. Administering vitamin D as a standard postoperative treatment regimen may be helpful in reducing this deficiency. We, therefore, recommend continuous monitoring of vitamin D, PTH, and serum Ca levels after surgery to manage these issues effectively.

The Effect of Vitamin D Supplementation on Serum 25-Hydroxy Vitamin D in the Patients Undergoing Bariatric Surgery: a Systematic Review and Meta-Analysis of Randomized Clinical Trials

Currently, there is no consensus on the optimal vitamin D administration in bariatric patients. The present systematic review and meta-analysis were conducted to examine the effect of vitamin D supplements on serum level of 25(OH) vitamin D in the patients undergoing bariatric surgery (BS).Random model effects were used to estimate standardized mean difference (SMD) with a 95% confidence interval (CI). Nine clinical trials were included in the meta-analysis. Vitamin D supplementation in patients undergoing BS modestly improves vitamin D status (SMD, 0.53; 95% CI, 0.28, 0.77) particularly, in the dosages above 2850 IU/day and in the patients with BMI greater than 50 kg/m². Vitamin D supplementation was associated with prevention of raising of the PTH serum concentration and without impact on serum calcium levels.

Changes in Nutritional Outcomes After Sleeve Gastrectomy: a Systematic Review and Meta-analysis

PURPOSE

The aim of this meta-analysis is to evaluate the changes in nutritional indicators in individuals with obesity before and after SG.

MATERIALS AND METHODS

A systematic retrieval of the available literature was performed using PubMed, Embase, Web of Science, and Chinese National Knowledge Infrastructure databases. The following indicators were evaluated: serum 25-hydroxyvitamin D [25(OH)D], calcium, phosphorus, iron, vitamin B12, folate, magnesium, and zinc from pre-operation to post-operation.

RESULTS

A total of 38 studies met inclusion criteria. A significant increase was observed in serum 25(OH)D (SMD = 0.70, 95%CI 0.38 to 1.02, P < 0.001), phosphorus (SMD = 0.40, 95%CI 0.14 to 0.67, P = 0.003), iron (SMD = 0.50, 95%CI 0.38 to 0.62, P < 0.001), and folate (SMD = 0.37, 95%CI 0.09 to 0.65, P = 0.01) after SG. Nevertheless, the increasing trend of serum phosphorus (P = 0.143) and folate (P = 0.774) disappeared in the unprescribed subgroup. A significant decrease in serum zinc (SMD =  - 0.41, 95%CI - 0.81 to - 0.01, P = 0.044) was found after SG. No significant changes in serum calcium (SMD = 0.08, 95%CI - 0.09 to 0.25, P = 0.372), vitamin B12 (SMD = 0.10, 95%CI - 0.13 to 0.33, P = 0.398), and magnesium (SMD = 0.24, 95%CI - 0.10 to 0.58, P = 0.169) were observed. However, a significant decrease in serum calcium (P = 0.042) and vitamin B12 (P = 0.037) was found in the unprescribed subgroup.

CONCLUSIONS

Serum 25(OH)D, phosphorus, iron, and folate levels improved after a careful monitoring and due to a rigorous supplementation. The optimal dose of calcium, magnesium, and zinc supplementation has yet to be established; therefore, a broader supplementation of trace elements and minerals has to be suggested.

Adherence to Nutritional Supplementation Determines Postoperative Vitamin D Status, but Not Levels of Bone Resorption Marker, in Sleeve-Gastrectomy Patients

BACKGROUND

Taking advantage of isomeric form of vitamin E in the supplement, adherence to supplement could be evaluated by changes in circulating α- and γ-tocopherol concentrations. Accordingly, effects of supplementation on postoperative nutrition and bone metabolism were studied in terms of adherence.

METHODS

Thirty-eight SG patients were all prescribed a postoperative nutritional supplement containing a low dose of vitamin D (600 IU) and calcium (200 mg). Blood samples were collected prior to (M0) and 6 months after (M6) surgery and concentrations of nutrients and C-terminal telopeptide of type I collage (CTX), a marker of bone resorption, were measured. Adherence and non-adherence were stratified according to change (△, M6-M0) in serum α-tocopherol concentrations (> 0 vs. ≤ 0, respectively).

RESULTS

When M0 and M6 were compared, there were significant increases in serum concentrations of 25(OH)D, α-tocopherol and selenium, whereas there were reductions in parathyroid hormone, ferritin, and γ-tocopherol. At M6, the prevalence of vitamin D insufficiency (25(OH)D < 30 ng/mL) and high CTX were 72 and 26%, respectively. When comparison was made between adherence and non-adherence, only △25(OH)D concentrations, but no other nutrients nor postoperative CTX differed. Multiple linear regression demonstrated that postoperative vitamin D status was independently associated with its preoperative concentrations (β = 0.85, p < 0.001) and adherence (β = 0.52, p < 0.05).

CONCLUSION

SG patients' adherence to supplementation, even with a low dose of vitamin D and calcium, determined vitamin D status but not bone resorption marker concentrations, at least within 6 months after surgery.

Differential Behavior of 25(OH)D and f25(OH)D3 in Patients with Morbid Obesity After Bariatric Surgery

BACKGROUND

Total 25-OH-vitamin D (25(OH)D) levels are decreased in patients with obesity, but few data exist regarding free-vitamin D3 (f25(OH)D3) concentrations. We aimed to evaluate the effect of bariatric surgery on 25(OH)D and f25(OH)D3 in a cohort of patients with morbid obesity.

METHODS

Twenty-four patients submitted to sleeve gastrectomy (SG) (mean age 48 years, body mass index (BMI) 48.16±10.73k/m²) were evaluated before and 1 year after surgery. Anthropometric data, parathormone (PTH), calcium, alkaline phosphatase, 25(OH)D, and f25(OH)D3 were recorded.

RESULTS

25(OH)D and f25(OH)D3 correlated well before and after SG. Baseline determinations did not correlate with BMI, but they inversely correlated with BMI 1 year after surgery (r_s=-0.46, p=0.02 and r_s=-0.60, p=0.002, respectively). Post-surgery % total body weight loss (%TBWL) was 27.4±13.8 %; f25(OH)D3 concentrations increased significantly (5.28±2.29 pg/mL vs 6.64±2.25 pg/mL; p=0.03), whereas 25(OH)D did not change. Patients who achieved a BMI <35 kg/m² 1 year after surgery had significantly higher concentrations of f25(OH)D3 (7.9±1 pg/mL vs 4.8±1.1, p<0.001) and 25(OH)D (30.9±9.4 ng/mL vs 22.3±13.4; p=0.03) compared to those who remained with BMI >35 kg/m².

CONCLUSION

There is a significant inverse relationship between BMI and both f25(OH)D3 and 25(OH)D 1 year after surgery. Only f25(OH)D3 concentrations increased 1 year after surgery, which could be explained by a greater f25(OH)D3 sequestration before SG in the adipose tissue, potentially due to the more liposoluble nature of f25(OH)D3 than the protein-bound form 25(OH)D.

Vitamin D Status After Gastric Bypass or Sleeve Gastrectomy over 4 Years of Follow-up

BACKGROUND

Bariatric surgery for severe obesity can lead to micronutrient/vitamin deficiencies.

AIMS

To study baseline and post-surgical prevalence of vitamin D deficiency in patients undergoing bariatric surgery.

PARTICIPANTS AND SETTING

Patients undergoing bariatric surgery in a university teaching hospital in North West England.

METHODS

We performed an observational cohort analysis of longitudinal data on vitamin D and related parameters in patients who underwent bariatric surgery. Patients were routinely recommended daily combined calcium and vitamin D supplementation post-surgery.

RESULTS

We studied 460 patients who had completed at least 12 months post-operatively; mean (standard deviation) age was 48.0 (10.5) years, weight 144.7 (27.3) kg and body mass index 50.0 (7.6) kg/m²; 292 (63.5%) underwent gastric bypass and 168 (36.5%) sleeve gastrectomy. Vitamin D level was 33.1 (23.9) nmol/L at baseline, rising to 57.1 (23.1) nmol/L at 12 months post-surgery. Whereas 43.2% had vitamin D deficiency and 34.7% insufficiency preoperatively, 8.9% and 26.7% had deficiency and insufficiency, respectively, at 12 months with similar trends up to 4 years of follow-up. There were no significant differences between procedures or sexes in vitamin D levels or sufficiency rates.

CONCLUSION

Vitamin D deficiency and insufficiency were prevalent pre-surgery and reduced significantly with routine supplementation post-surgery.

The True Story on Deficiencies After Sleeve Gastrectomy: Results of a Double-Blind RCT

BACKGROUND

Since a few years, the laparoscopic sleeve gastrectomy (SG) has become the most performed bariatric operation worldwide. However, as with all bariatric procedures, SG also leads to vitamin and mineral deficiencies post-operatively and standard multivitamin supplements are probably not sufficient.

OBJECTIVE

The present study evaluates the effectiveness of a specialized multivitamin supplement for SG patients (WLS Optimum 1.0, FitForMe, Rotterdam, the Netherlands), compared to a standard multivitamin supplement (sMVS).

DESIGN

A double-blind randomized controlled trial was performed. For 12 months, patients in the intervention group received WLS Optimum, containing elevated doses of multiple vitamins and minerals. Patients in the control group were provided with sMVS, containing 100% of the recommended dietary allowance.

RESULTS

In total, 139 patients were available for analysis (WLS Optimum, n = 69; sMVS, n = 70). Intention-to-treat analyses revealed more folic acid deficiencies and higher serum vitamin B1 levels in the WLS Optimum group. Per protocol analyses showed that in patients using WLS Optimum, serum folic acid and vitamin B1 levels were higher, serum PTH levels were lower, and only one patient (2.6%) was anemic compared to 11 patients (17.5%) using a sMVS (p < 0.05 for all). No differences were found in prevalence of deficiencies for iron, vitamin B12, vitamin D, and other vitamins and minerals.

CONCLUSIONS

This optimized multivitamin supplement only affected serum levels of folic acid, PTH and vitamin B1, and anemia rates compared to a sMVS. There is a clear need to further optimize multivitamin supplementation for SG patients. Besides, non-compliance with multivitamin supplements remains an important issue that should be dealt with.

CLINICAL TRIAL REGISTRY

The study protocol was registered at the clinical trials registry of the National Institutes of Health (ClinicalTrials.gov; identifier NCT01609387).

Recommendations for nutritional care after bariatric surgery: Recommendations for best practice and SOFFCO-MM/AFERO/SFNCM/expert consensus

Nutritional care after bariatric surgery is an issue of major importance, especially insofar as risk of deficiency has been extensively described in the literature. Subsequent to the deliberations carried out by a multidisciplinary working group, we are proposing a series of recommendations elaborated using the Delphi-HAS (official French health authority) method, which facilitates the drawing up of best practice and consensus recommendations based on the data of the literature and on expert opinion. The recommendations in this paper pertain to dietary management and physical activity, multivitamin and trace element supplementation and the prevention and treatment of specific deficiencies in vitamins B1, B9, B12, D and calcium, iron, zinc, vitamins A, E and K, dumping syndrome and reactive hypoglycemia.

British Obesity and Metabolic Surgery Society Guidelines on perioperative and postoperative biochemical monitoring and micronutrient replacement for patients undergoing bariatric surgery-2020 update

Bariatric surgery is recognized as the most clinically and cost-effective treatment for people with severe and complex obesity. Many people presenting for surgery have pre-existing low vitamin and mineral concentrations. The incidence of these may increase after bariatric surgery as all procedures potentially cause clinically significant micronutrient deficiencies. Therefore, preparation for surgery and long-term nutritional monitoring and follow-up are essential components of bariatric surgical care. These guidelines update the 2014 British Obesity and Metabolic Surgery Society nutritional guidelines. Since the 2014 guidelines, the working group has been expanded to include healthcare professionals working in specialist and non-specialist care as well as patient representatives. In addition, in these updated guidelines, the current evidence has been systematically reviewed for adults and adolescents undergoing the following procedures: adjustable gastric band, sleeve gastrectomy, Roux-en-Y gastric bypass and biliopancreatic diversion/duodenal switch. Using methods based on Scottish Intercollegiate Guidelines Network methodology, the levels of evidence and recommendations have been graded. These guidelines are comprehensive, encompassing preoperative and postoperative biochemical monitoring, vitamin and mineral supplementation and correction of nutrition deficiencies before, and following bariatric surgery, and make recommendations for safe clinical practice in the U.K. setting.

Metabolic syndrome and liver disease in the era of bariatric surgery: What you need to know!

Metabolic syndrome (MS) is defined as the constellation of obesity, insulin resistance, high serum triglycerides, low high-density lipoprotein cholesterol, and high blood pressure. It increasingly affects more and more people and progressively evolves into a serious issue with widespread healthcare, cost, and quality of life associated consequences. MS is associated with increased morbidity and mortality due to cardiovascular or chronic liver disease. Conservative treatment, which includes diet, exercise, and antidiabetic agents, is the mainstay of treatment, but depends on patient compliance to medical treatment and adherence to lifestyle modification recommendations. Bariatric surgery has recently emerged as an appropriate alternative treatment with promising long-term results. Sleeve gastrectomy and Roux-en-Y gastric bypass constitute the most commonly performed procedures and have been proven both cost-effective and safe with low complication rates. Liver transplantation is the only definitive treatment for end-stage liver disease and its utilization in patients with non-alcoholic steatohepatitis has increased more than fivefold over the past 15 years. In this review, we summarize current state of evidence on the surgical treatment of MS.

Analysis of vitamin levels and deficiencies in bariatric surgery patients: a single-institutional analysis

BACKGROUND

Bariatric surgery patients are at risk for vitamin deficiencies.

OBJECTIVES

Investigate the prevalence of deficiencies of vitamins A, B1, B12, D, and folate in sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) patients in a single institution.

SETTING

An academic medical center.

METHODS

Retrospective chart reviews of 468 bariatric surgery patients (358 SG and 110 RYGB) were analyzed for vitamin levels, calcium, and parathyroid hormone. Both preoperative and postoperative measurements were obtained.

RESULTS

Deficiency of vitamin D was the most common, seen in 27% preoperatively. Postoperatively, RYGB patients had a higher prevalence of vitamin D deficiency than SG patients (11.5% RYGB versus 5.2% SG within the first postoperative year, and 20.3% RYGB versus 13.4% SG after 1 year). Elevated parathyroid hormone was observed in 45% of RYGB patients after 1 year postoperatively. Vitamin A deficiency was uncommon preoperatively (2.7% SG versus 1.7% RYGB), but increased after surgery (9.4% SG versus 15.9% RYGB within 1 year postoperatively, and 5.2% SG versus 7.7% RYGB after 1 year). Vitamin B1 deficiency was observed in 8.1% SG versus 1.7% RYGB patients preoperatively and increased during the first year postoperatively (SG 10.5% and RYGB 13.7%), but improved after 1 year (7.2% SG versus 5.9% RYGB). Less than 2% of Vitamin B12 deficiencies and no folate deficiencies occurred in both SG and RYGB patients.

CONCLUSIONS

The highest prevalence of vitamin B1 and A deficiencies were seen in the first year postoperatively. Vitamin B12 and folate deficiency were uncommon in our patients. Vitamin D deficiency improved after surgery, but elevated parathyroid hormone was common after RYGB.

Calcium absorption may be affected after either sleeve gastrectomy or Roux-en-Y gastric bypass in premenopausal women: a 2-y prospective study

Background

Although Roux-en-Y gastric bypass (RYGBP) is known to reduce calcium absorption (CA), the effects of vertical sleeve gastrectomy (SG) and its long-term implications on CA have not yet been studied.

Objective

The aim of this study was to evaluate changes in CA and its relation with modifications of bone mineral density (BMD), intakes of calcium and vitamin D, vitamin D status, and parathyroid hormone (PTH) concentrations ≤24 mo after SG and RYGBP, respectively.

Design

Twenty-six premenopausal women undergoing SG [mean ± SD body mass index (BMI; kg/m2): 37.3 ± 3.2; age: 34.2 ± 10.2 y] and 32 undergoing RYGBP (BMI: 42.0 ± 4.2; age: 37.3 ± 8.1 y) were studied at baseline (presurgery) and followed up at 12 and 24 mo after surgery. BMD, bone alkaline phosphatase activity, and serum PTH, 25-hydroxyvitamin D [25(OH)D], calcium, magnesium, and phosphorus concentrations were determined. Food and supplement intakes were recorded. CA was measured by using a dual stable isotope method.

Results

In premenopausal women, CA was significantly reduced from 36.5% ± 2.0% preoperatively to 21.0% ± 2.3% and 18.8% ± 3.4% at 12 and 24 mo post-SG surgery, respectively. CA also decreased significantly from 41.5% ± 2.8% preoperatively to 27.9% ± 3.8% and 18.5% ± 2.2% 12 and 24 mo after RYGBP, respectively. No difference was found between type of surgery (time × group interaction, P = 0.60). Considering both groups combined, 56.6% of the variance in CA at the 12-mo but not at the 24-mo follow-up was explained by serum PTH and 25(OH)D concentrations, together with vitamin D and calcium intakes.

Conclusions

CA was similarly reduced in both SG and RYGBP compared with baseline, and it was not associated with changes in BMD or body weight loss. This reduction in CA could be explained only partially by calcium intake increase. This trial is registered at http://www.isrctn.com as ISRCTN31937503.

Vitamin D Metabolism in Bariatric Surgery

Hypovitaminosis D is common in obese patients and persists after roux-en-Y gastric bypass and sleeve gastrectomy. Several societies recommend screening for vitamin D deficiency before bariatric surgery, and replacement doses of 3000 IU/d and up to 50,000 IU 1 to 3 times per week, in case of deficiency, with periodic monitoring. These regimens are mostly based on expert opinion. Large trials are needed to assess the vitamin D dose response, by type of bariatric surgery, and evaluate the effect on surrogate markers of skeletal outcomes. Such data are essential to derive desirable vitamin D levels in this population.

Bariatric surgery and long-term nutritional issues

Bariatric surgery is recognized as a highly effective therapy for obesity since it accomplishes sustained weight loss, reduction of obesity-related comorbidities and mortality, and improvement of quality of life. Overall, bariatric surgery is associated with a 42% reduction of the cardiovascular risk and 30% reduction of all-cause mortality. This review focuses on some nutritional consequences that can occur in bariatric patients that could potentially hinder the clinical benefits of this therapeutic option. All bariatric procedures, to variable degrees, alter the anatomy and physiology of the gastrointestinal tract; this alteration makes these patients more susceptible to developing nutritional complications, namely, deficiencies of macro- and micro-nutrients, which could lead to disabling diseases such as anemia, osteoporosis, protein malnutrition. Of note is the evidence that most obese patients present a number of nutritional deficits already prior to surgery, the most important being vitamin D and iron deficiencies. This finding prompts the need for a complete nutritional assessment and, eventually, an adequate correction of pre-existing deficits before surgery. Another critical issue that follows bariatric surgery is post-operative weight regain, which is commonly associated with the relapse of obesity-related co-morbidities. Nu-tritional complications associated with bariatric surgery can be prevented by life-long nutritional monitoring with the administration of multi-vitamins and mineral supplements according to the patient's needs.