Vitamin and mineral deficiencies following obesity surgery

Any obesity operation, whether malabsorptive or based upon the production of early satiety, produces weight loss by causing a net reduction in the delivery of nutrients to the portal circulation. The malabsorption caused by jejunoileal bypass produces numerous severe micronutrient deficiencies along with other potentially damaging conditions. Although there are numerous reports of such deficiencies following gastric restrictive procedures (particularly gastric bypass), the conditions are almost always more easily treated than those after intestinal bypass, and resultant clinical illnesses are rare. Physicians should be aware that any obesity procedure carries a risk of nutritional deficiency.     

Impairment of vitamin D metabolism and bone mineral content after intestinal bypass for obesity. A longitudinal study

Ten obese subjects who had undergone intestinal bypass operation (end-to-side jejunoileostomy) were studied longitudinally with respect to vitamin D and other indices of calcium metabolism. Investigations were carried out before operation (t0) and after 6 months (t1), 12 months (t2), and a mean of 54 months (range, 49-58 months) (t3) postoperatively. Serum 25-hydroxyvitamin D (25OHD) was subnormal at t0 but after operation values declined gradually to an extremely low level at t3, possibly because of a loss through malabsorption. Serum 24,25-dihydroxyvitamin D remained normal at t1 and t2 but fell to about half the normal level at t3, probably owing to lack of its precursor, 25OHD. In contrast, serum 1,25-dihydroxyvitamin D (1,25(OH)2D) remained normal throughout the study, indicating a marked stimulation of kidney 1 alpha-hydroxylase activity. Serum calcium fell rapidly to a constant subnormal level, and it is concluded that the serum calcium malabsorption is due to factors other than impaired 1,25(OH)2D activity. Bone mineral content (BMC) was unchanged between t0 and t2, but thereafter (between t2 and t3) the mean BMC fell rapidly to about 90% of preoperative value, possibly due to a defective bone mineralization in the late postoperative period. The findings indicate a high risk of bone disease developing after intestinal bypass operation. Substitution with calcium and vitamin D should be given to these patients, but the optimal vitamin D metabolite (or combination of metabolites) for such treatment is still unknown.     

Effect of vitamin B12 and folic acid deficiencies on neutrophil function.

Morphological and quantitative neutrophil abnormalities are common in the megaloblastic anemias of vitamin B12 and folic acid deficiency. Little is known, however, about the role of these vitamins in normal leukocyte function. Seven patients with megaloblastic bone marrows, four with vitamin B12 deficiency and three with folic acid deficiency, were studied to determine the effect, if any, of these deficiencies on leukocyte function. Phagocytosis of staphylococci, hexose monophosphate shunt activation with phagocytosis, and microbicidal capacity against Staphylococcus aureus were determined prior to the institution of specific therapy. In two instances, these studies were repeated following treatment. There was no impairment of phagocytosis per se, and resting metabolism was not significantly decreased. With phagocytosis, however, metabolic activation was decreased to 35%-36% of control values in the leukocytes of patients with vitamin B12 deficiency but not in the leukocytes of patients with folic acid deficiency. Bacterial killing was slightly decreased in vitamin B12 but not in folic acid deficiency. These abnormalities of function were reversed after specific therapy. These findings suggested a specific role for vitamin B12 in the production of intermediates necessary for normal cell function.     

Effect of concurrent vitamin a and iodine deficiencies on the thyroid-pituitary axis in rats.

Objective: Deficiencies of vitamin A and iodine are common in many developing countries. Vitamin A deficiency (VAD) may adversely affect thyroid metabolism. The study aim was to investigate the effects of concurrent vitamin A and iodine deficiencies on the thyroid-pituitary axis in rats. Design: Weanling rats (n = 56) were fed diets deficient in vitamin A (VAD group), iodine (ID group), vitamin A and iodine (VAD + ID group), or sufficient in both vitamin A and iodine (control) for 30 days in a pair-fed design. Serum retinol (SR), thyroid hormones (FT(4), TT(4), FT(3), and TT(3)), serum thyrotropin (TSH), pituitary TSHbeta mRNA expression levels, and thyroid weights were determined at the end of the depletion period. Main outcome: Compared to the control and ID groups, SR concentrations were about 35% lower in the VAD and VAD + ID groups (p < 0.001), indicating moderate VA deficiency. Comparing the VAD and control groups, there were no significant differences in TSH, TSHbeta mRNA, thyroid weight, or thyroid hormone levels. Compared to the control group, serum TSH, TSHbeta mRNA, and thyroid weight were higher (p < 0.05), and FT4 and TT4 were lower (p < 0.001), in the VAD + ID and ID groups. Compared to the ID group, TSH, TSHbeta mRNA, and thyroid weight were higher (p < 0.01) and FT(4) and TT(4) were lower (p < 0.001) in the VAD + ID group. There were no significant differences in TT3 or FT3 concentrations among groups. Conclusion: Moderate VAD alone has no measurable effect on the pituitary-thyroid axis. Concurrent ID and VAD produce more severe primary hypothyroidism than ID alone.     

Severe hypoglycaemia post-gastric bypass requiring partial pancreatectomy: evidence for inappropriate insulin secretion and pancreatic islet hyperplasia

Aims/hypothesis Postprandial hypoglycaemia following gastric bypass for obesity is considered a late manifestation of the dumping syndrome and can usually be managed with dietary modification. We investigated three patients with severe postprandial hypoglycaemia and hyperinsulinaemia unresponsive to diet, octreotide and diazoxide with the aim of elucidating the pathological mechanisms involved.Methods Glucose, insulin, and C-peptide were measured in the fasting and postprandial state, and insulin secretion was assessed following selective intra-arterial calcium injection. Pancreas histopathology was assessed in all three patients.Results All three patients had evidence of severe postprandial hyperinsulinaemia and hypoglycaemia. In one patient, reversal of gastric bypass was ineffective in reversing hypoglycaemia. All three patients ultimately required partial pancreatectomy for control of neuroglycopenia; pancreas pathology of all patients revealed diffuse islet hyperplasia and expansion of beta cell mass.Conclusions/interpretation These findings suggest that gastric bypass-induced weight loss may unmask an underlying beta cell defect or contribute to pathological islet hyperplasia, perhaps via glucagon-like peptide 1-mediated pathways.     

New aspects of vitamin K prophylaxis

Vitamin K-deficiency bleeding (VKDB) is rare, unpredictable, and life-threatening. Warning signs such as minimal bleeds, evidence of cholestasis, and failure to thrive often are present but overlooked. Therefore VK prophylaxis is necessary, at least for breastfed infants. Most effective is the intramuscular application, which unfortunately has real disadvantages (trauma, poor acceptance by parents) and potential risks due to very high VK levels, since VK affects not only coagulation but all processes associated with carboxylation. Three oral doses of VK protect many babies (2-mg doses giving better protection than 1 mg) but the prevention of VKDB is not assured even with the mixed-micelle preparation. Use of small VK doses either daily or weekly seems to give effective prophylaxis without the adverse effects of intramuscular VK application. The risks of VKDB are minimized if prophylaxis recommendations are followed and if warning signs are recognized and promptly acted upon. The next goal is the search for methods of identifying early the few infants destined to bleed so that targeted prophylaxis can replace the current "prophylaxis for all."     

Vitamin D and mineral deficiencies increase the plasma membrane calcium pump of chicken intestine.

The basolateral membrane of the enterocyte was previously shown to contain an adenosine triphosphate-dependent calcium pump. Using immunological procedures, the localization of the Ca2+ pump in chick intestine, and the effect of dietary variables on the concentration of the pump, were studied. A monoclonal antibody produced against the human erythrocyte calcium pump was shown to cross-react with a chick intestinal Ca2+ pump epitope. The most intense staining of intestinal tissue, as determined immunohistochemically, occurred at the basolateral membrane of the duodenum, jejunum, ileum, and colon, with minor staining elsewhere. By the Western blotting procedure, vitamin D repletion of vitamin D-deficient chicks was shown to significantly increase the concentration of the Ca2+ pump epitope of duodenal, jejunal, and ileal mucosa by a factor of 2-3. Chicks were also fed diets deficient in calcium or phosphorus, a situation known to result in the stimulation of the synthesis of calbindin-D28k and an enhancement of the efficiency of Ca2+ absorption. Adaptation of the chicks to these deficient diets was verified by an increase in intestinal levels of calbindin-D28k, and is now shown to increase the Ca2+ pump epitope. From these immunological studies, it seems apparent that dietary variables that enhance intestinal Ca2+ absorption also increase the amount of the intestinal basolateral Ca2+ pump.     

Bone mineral status in growth hormone-deficient males with isolated and multiple pituitary deficiencies of childhood onset.

In order to determine whether growth hormone (GH) deficiency of childhood onset affects the adult bone mineral status, we assessed bone mineral content (BMC) by photon absorptiometry in 30 full-grown GH-deficient men (8 with isolated GH deficiency and 22 with multiple pituitary deficiencies; 28 previously treated with GH) and in 30 male controls matched for age (within 4 yr) and height (within 10 cm). Forearm BMC was measured by single photon absorptiometry just proximally of the distal one third of the nondominant forearm (PBMC-2 in arbitrary units and PBMC/bone width (BW) after normalization for bone width) and at a more distal site, close to the carpal joint (DBMC-2 and DBMC/BW). Lumbar BMC was measured by dual photon absorptiometry and reported as total BMC for L2-L4 (LBMC in g) and after normalization for projected area (LBMD in g/cm2). The patients had a significantly lower BMC, both at the forearm (P less than 0.0001) and at the lumbar spine (P less than 0.005): 35.7 +/- 1.0 vs. 50.0 +/- 1.6 and 36.9 +/- 1.2 vs. 52.8 +/- 1.9 (mean +/- SEM) for PBMC-2 and DBMC-2 in patients and controls, respectively; 1.36 +/- 0.03 vs. 1.70 +/- 0.04 and 1.07 +/- 0.03 vs. 1.35 +/- 0.04 for PBMC/BW and DBMC/BW; 34.00 +/- 1.08 vs. 42.02 +/- 1.27 g for LBMC and 0.886 +/- 0.016 vs. 0.976 +/- 0.018 g/cm2 for LBMD. Both the patients with isolated GH deficiency and the patients with multiple pituitary deficiencies were osteopenic when compared to their respective controls (P less than 0.01 to P less than 0.0001 for the patients with multiple deficiencies; statistical significance reached for PBMC-2, DBMC-2, and DBMC/BW only, P less than 0.05, in the small group of patients with isolated GH deficiency). For the patients (n = 19) who had at least three serial measurements over a period of 6 to 28 months, no decrease in BMC was detected. Our findings indicate that men with GH deficiency of childhood onset present with a low adult bone mass, despite prior GH substitution in most of these subjects. The observations of a more pronounced bone mineral deficit at the forearm (20-30% lower mean values, depending on the type of measurements) than at the lumbar spine (9-19%) and the findings of osteopenia in both the patients with isolated GH deficiency and multiple pituitary deficiencies, support the view that GH deficiency per se is responsible for part of the observed deficit.(ABSTRACT TRUNCATED AT 400 WORDS)     

Antibiotic prophylaxis for cardiovascular surgery. Efficacy with coronary artery bypass

Two hundred twenty patients were randomly assigned to receive either ceforanide or cephalothin as perioperative antibiotic prophylaxis during cardiovascular surgery. More infections were seen among cephalothin recipients (8 deep, 32 total) than among ceforanide recipients (1 deep, 17 total). Among patients who had only coronary artery bypass grafting, more cephalothin recipients had infection than did ceforanide recipients (19 of 82 as opposed to 7 of 83; p = 0.001; relative risk, 2.7; 95% confidence interval, 1.22 to 6.18). The difference between the two regimens was attributable to fewer blood, wound, and urinary tract infections. Among patients who had other procedures, there was no difference in the efficacy of the two regimens. Cephalothin recipients who developed wound or blood stream infections had lower antibiotic levels in their atrial appendages than recipients not developing such infections (p = 0.02). If one assumes that cephalothin does not increase the risk of infection, then these data show that antibiotic prophylaxis prevents infection after coronary artery bypass surgery, and, in the dosages used, that ceforanide is superior to cephalothin.     

Complications of bariatric surgery: Dumping syndrome,reflux and vitamin deficiencies

Bariatric surgical procedure are increasingly and successfully applied in the treatment of morbid obesity. Nevertheless, these procedures are not devoid of potential long-term complications. Dumping syndrome may occur after procedures involving at least partial gastric resection or bypass, including Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy. Diagnosis is based on clinical alertness and glucose tolerance testing. Treatment may involve dietary measures, acarbose and somatostatin analogues, or surgical reintervention for refractory cases. Gastro-esophageal reflux disease (GERD) can be aggravated by vertical banded gastroplasty and sleeve gastrectomy procedures, but pre-existing GERD may improve after RYGB and with adjustable gastric banding. Nutrient deficiencies constitute the most important long-term complications of bariatric interventions, as they may lead to haematological, metabolic and especially neurological disorders which are not always reversible. Malabsorptive procedures, poor postoperative nutrient intake, recurrent vomiting and poor compliance with vitamin supplement intake and regular follow-up are important risk factors. Preoperative nutritional assessment and rigourous postoperative follow-up plan with administration of multi-vitamin supplements and assessment of serum levels is recommended in all patients.     

Nervous and ocular disorders in children with cholestasis and vitamin A and E deficiencies

Thirteen children, aged 10 months to 20 years, presenting with chronic cholestasis from the first month of life and with low serum levels of vitamins A and/or E, have been investigated for neurological and ophthalmological symptoms. Clinical findings consisted of 4 types: peripheral neuropathy; cerebellar dysfunction; abnormalities of eye movement, and retinal degenerative changes. The results of electrophysiological and morphological studies of muscle and nerves were consistent with neurono-axonal degeneration. Electrical abnormalities of the retina, especially a decrease of the b wave of electroretinogram, appear to be the first sign of the syndrome, allowing early detection. Evidence for vitamin deficiency (E or E+A) suggests substitutive parenteral treatment in such patients.