Elevated methylmalonic acid and total homocysteine levels show high prevalence of vitamin B12 deficiency after gastric surgery

Vitamin B12 deficiency

Of the water-soluble vitamins, vitamin B12 (B12) has the lowest daily requirement. It also has several unique properties including a complex pathway for its absorption and assimilation requiring intact gastric and terminal small intestinal function, an enterohepatic pathway, and several dedicated binding proteins and chaperons. The many causes of B12 deficiency include malabsorption and defects in cellular delivery and uptake, as well as limited dietary intake. B12 is required as a cofactor for only two reactions in humans, the cytosolic methionine synthase reaction and the mitochondrial methymalonyl CoA mutase reaction. Disruption of either of these reactions gives rise to B12 deficiency. Although more common with advancing age, because of the higher prevalence of malabsorptive disorders in the elderly, B12 deficiency is widely distributed across all age groups particularly where food insecurity occurs. The consequences and severity of B12 deficiency are variable depending on the degree of deficiency and its duration. Major organ systems affected include the blood, bone marrow and nervous system. Megaloblastic anemia results from a defect in thymidine and therefore DNA synthesis in rapidly dividing cells. Nervous system involvement is varied, some of which results from defective myelin synthesis and repair. Cognitive impairment and psychosis may also occur. Diagnosis of B12 deficiency rests on clinical suspicion followed by laboratory testing, which consists of a panel of tests, that together provide clinically reliable predictive indices. B12 metabolism and deficiency is closely intertwined with folate, another B-vitamin. This chapter explores the various aspects of a unique and fascinating micronutrient.

A facile and economic electrochemical sensor for methylmalonic acid: a potential biomarker for vitamin B12 deficiency

A facile and cost-effective method based on a modified pencil graphite electrode (PGE) has been developed for sensing of methylmalonic acid (MMA). The fabricated sensor showed a linear dynamic range (0.50 pM–55 nM) and a LOD of (0.16 pM).

Hyperhomocysteinemia: Clinical Insights

Homocysteine (Hcy) is a sulfhydryl-containing amino acid, and intermediate metabolite formed in metabolising methionine (Met) to cysteine (Cys); defective Met metabolism can increase Hcy. The effect of hyperhomocysteinemia (HHcy) on human health, is well described and associated with multiple clinical conditions. HHcy is considered to be an independent risk factor for common cardiovascular and central nervous disorders, where its role in folate metabolism and choline catabolism is fundamental in many metabolic pathways. HHcy induces inflammatory responses via increasing the pro-inflammatory cytokines and downregulation of anti-inflammatory cytokines which lead to Hcy-induced cell apoptosis. Conflicting evidence indicates that the development of the homocysteine-associated cerebrovascular disease may be prevented by the maintenance of normal Hcy levels. In this review, we discuss common conditions associated with HHcy and biochemical diagnostic workup that may help in reaching diagnosis at early stages. Furthermore, future systematic studies need to prove the exact pathophysiological mechanism of HHcy at the cellular level and the effect of Hcy lowering agents on disease courses.

Vitamin B12 Deficiency Among the Healthy Jordanian Adult Population: Diagnostic Levels, Symptomology and Risk Factors

BACKGROUND

Compared to the data available for developed countries, there is a marked scarcity of information on the levels and symptomology of vitamin B₁₂ deficiency in developing countries, particularly in the Middle Eastern region.

OBJECTIVE

To explore (a) the risk factors associated with a deficiency of vitamin B₁₂, and (b) the baseline (cut-off) serum level of vitamin B₁₂ for a clinically-symptomatic deficiency in the Jordanian adult population.

METHODS

A total of 485 subjects were included in this study. Blood samples were drawn for biochemical analysis and data regarding socio-demographics, general health, anthropometric measures, and past medical, surgical, and medication history were collected. To explore the cut-off point, we compared all parameters included in a standard complete blood count as well as the main symptoms reported to be associated with B₁₂ deficiency between groups of different B₁₂ cut-off values, consisting of those above and below 200, 175, 150 and 125 pg/ml.

RESULTS

Low dairy intake habits, age, recurrent headaches, heartburn, and peptic ulcer disease were found to be significantly associated with lower vitamin B₁₂ levels. Surprisingly, daily smoking was associated with significantly higher B₁₂ levels. The results revealed that none of the included potential indicators of B₁₂ deficiency could be considered an indicative feature of deficiency. There were no significant differences neither in the symptoms nor in the CBC parameters between any of the tested study groups.

CONCLUSION

Low dairy intake, older ages, recurrent headaches, heartburn, and peptic ulcer disease all could be considered as risk factors of having low vitamin B₁₂ levels within the Jordanians. Also, they tend to have lower levels of vitamin B₁₂ levels, in comparison to countries in the West, without necessarily having deficiency symptoms. The cut-off value to diagnose functional B₁₂ deficiency could be less than 125 pg/ml for the Jordanians. More local studies are needed to establish an accurate vitamin B₁₂ cut-off value for the population in Jordan.

Role of Functional Biomarkers to Identify Early Vitamin B12 Deficiency in Patients with Sleeve Gastrectomy: A Cross-Sectional Study

Background and objectives: Although laparoscopic sleeve gastrectomy (LSG) is effective for obesity management, postoperative vitamin B12 (B12) deficiency is of major concern. In this cross-sectional study, we assessed the levels of B12 and its related functional biomarkers, namely, total homocysteine (tHcy), methylmalonic acid (MMA), folate, methylcitric acid (MCA), and hemoglobin (Hb), in one-year postoperative LSG patients and matched controls. Materials and Methods: Plasma B12, tHcy, MMA, folate, and MCA were measured in matched controls (n = 66) and patients (n = 71) using validated liquid chromatography-tandem mass spectrometry techniques and protocols in the United Arab Emirates (UAE). Results: The median B12 concentration in patients (177 pmol/L) was significantly lower (p < 0.001) than in the controls (334.7 pmol/L). The tHcy and MMA levels were significantly increased (p < 0.001 and p = 0.011, respectively) and folate levels were significantly decreased (p = 0.001) in the LSG patients compared to the controls. Interestingly, no significant difference in MCA levels were observed between the two groups. The levels of tHcy and MMA were concomitantly increased with the decreased folate levels in postoperative LSG patients when compared with the controls. The Hb levels were significantly lower in males and females in the patient group compared with those in the control group, respectively (p = 0.005 and p = 0.043). Conclusions: This is the first report of serum levels of B12 and its functional biomarkers in postoperative LSG patients among a local population from the UAE. Our findings revealed significant alterations of the B12 biomarkers, total B12, MMA, and tHcy in one-year postoperative LSG patients.

Neuropathy by folic acid supplementation in a patient with anaemia and an untreated cobalamin deficiency: a case report

The rising rates of bariatric surgery (BS) are accompanied by neurological complications related to nutrient deficiencies. One of the risk factors for neurological complications in BS patients is poor vitamin and mineral supplementation. Prevention, diagnosis and treatment of these disorders are necessary parts of lifelong care after BS. Particularly important for optimal functioning of the nervous system are vitamin B₁ , B₆ , B₁₂ (cobalamin), E, copper and possibly vitamin B₁₁ (folic acid). In this case report, we narrate about a patient with anaemia and multiple vitamin and mineral deficiencies after Roux-en-Y gastric bypass (RYGB) with an alimentary limb of 150 cm and a biliopancreatic limb of 100 cm. RYGB is associated with an increased risk of vitamin deficiencies, especially a vitamin B₁₂ deficiency. The patient in this case report developed psychiatric-neurological symptoms due to folic acid supplementation in an untreated cobalamin deficiency. Second, we tried to elucidate the vitamin physiology to understand specific mechanisms after BS.

Anemia, Cancer, and Aging

BACKGROUND

Anemia is an issue of concern in the management of older patients with cancer. In this age group, the incidence and prevalence of both cancer and anemia increase with age.

METHODS

The clinical consequences and the management of anemia, a common comorbid condition in older patients with cancer, are explored.

RESULTS

Common causes of chronic anemia include iron deficiency and anemia of chronic disease. The prevalence of vitamin B12 deficiency due to reduced absorption of food-bound vitamin B12 also increases with aging. Although in many cases the cause of anemia is not found, a primary deficiency of erythropoietin may be at fault in at least some of these cases since the response of erythropoietin to anemia may decrease in individuals over age 70.

CONCLUSIONS

Anemia should not necessarily be ascribed to cancer or aging. The causes of anemia should be pursued and reversed, and hemoglobin levels should be maintained at a minimum of 12 g/dL in cancer patients undergoing chemotherapy who are responsive to erythropoietin. The reversal of anemia may offset or delay the accumulation of catabolic cytokines that may be responsible for functional decline in aging individuals.

Anemia for the Primary Care Physician

Anemia denotes a reduced red blood cell (RBC) mass from any cause. The causes of anemia are numerous and due to decreased (or abnormal) erythropoesis, shortened RBC life span, or blood loss. The most common etiology of anemia is iron deficiency. A judicious work up of anemia includes evaluating the reticulocyte count and peripheral smear. The severity of illness of a patient with anemia is determined by the degree of anemia and the seriousness of the underlying disorder. Management of patients with hereditary and hemolytic anemias should involve a hematologist.

Megaloblastic Anemias: Nutritional and Other Causes

Vitamin B₁₂ and folate deficiencies are major causes of megaloblastic anemia. Causes of B₁₂ deficiency include pernicious anemia, gastric surgery, intestinal disorders, dietary deficiency, and inherited disorders of B₁₂ transport or absorption. The prevalence of folate deficiency has decreased because of folate fortification, but deficiency still occurs from malabsorption and increased demand. Other causes include drugs and inborn metabolic errors. Clinical features of megaloblastic anemia include anemia, cytopenias, jaundice, and megaloblastic marrow morphology. Neurologic symptoms occur in B₁₂ deficiency, but not in folate deficiency. Management includes identifying any deficiency, establishing its cause, and replenishing B₁₂ or folate parenterally or orally.

Reduced folate and serum vitamin metabolites in patients with rectal carcinoma: an open-label feasibility study of pemetrexed with folic acid and vitamin B12 supplementation

The objectives of this single-center, open-label, phase II study were to evaluate (a) the feasibility and safety of neoadjuvant administration of pemetrexed with oral folic acid and vitamin B₁₂ (FA/B₁₂) in newly diagnosed patients with resectable rectal cancer and (b) intracellular and systemic vitamin metabolism. Patients were treated with three cycles of pemetrexed (500 mg/m², every 3 weeks) and FA/B₁₂ before surgery. The reduced folates tetrahydrofolate, 5-methyltetrahydrofolate, and 5,10-methylenetetrahydrofolate were evaluated from biopsies in tumor tissue and in adjacent mucosa. Serum levels of homocysteine, cystathionine, and methylmalonic acid were also measured. All 37 patients received three cycles of pemetrexed; 89.2% completed their planned dosage within a 9-week feasibility time frame. Neither dose reductions nor study drug-related serious adverse events were reported. Reduced folate levels were significantly higher in tumor tissue compared with adjacent mucosa at baseline. After FA/B₁₂ administration, tissue levels of reduced folates increased significantly and remained high during treatment in both tumor and mucosa until surgery. Serum levels of cystathionine increased significantly compared with baseline after FA/B₁₂ administration, but then decreased, fluctuating cyclically during pemetrexed therapy. Homocysteine and methylmalonic acid levels decreased significantly after FA/B₁₂ administration, and remained below baseline levels during the study. These results indicate that administration of three neoadjuvant cycles of single-agent pemetrexed, every 3 weeks, with FA/B₁₂ in patients with resectable rectal cancer is feasible and tolerable. Tissue and serum vitamin metabolism results demonstrate the influence of pemetrexed and FA/B₁₂ on vitamin metabolism and warrant further study.

Biomarkers and Algorithms for the Diagnosis of Vitamin B12 Deficiency

Vitamin B12 (cobalamin, Cbl, B12) is an indispensable water-soluble micronutrient that serves as a coenzyme for cytosolic methionine synthase (MS) and mitochondrial methylmalonyl-CoA mutase (MCM). Deficiency of Cbl, whether nutritional or due to inborn errors of Cbl metabolism, inactivate MS and MCM leading to the accumulation of homocysteine (Hcy) and methylmalonic acid (MMA), respectively. In conjunction with total B12 and its bioactive protein-bound form, holo-transcobalamin (holo-TC), Hcy, and MMA are the preferred serum biomarkers utilized to determine B12 status. Clinically, vitamin B12 deficiency leads to neurological deterioration and megaloblastic anemia, and, if left untreated, to death. Subclinical vitamin B12 deficiency (usually defined as a total serum B12 of <200 pmol/L) presents asymptomatically or with rather subtle generic symptoms that oftentimes are mistakenly ascribed to unrelated disorders. Numerous studies have now established that serum vitamin B12 has limited diagnostic value as a stand-alone marker. Low serum levels of vitamin B12 not always represent deficiency, and likewise, severe functional deficiency of the micronutrient has been documented in the presence of normal and even high levels of serum vitamin B12. This review discusses the usefulness and limitations of current biomarkers of B12 status in newborn screening, infant and adult diagnostics, the algorithms utilized to diagnose B12 deficiency and unusual findings of vitamin B12 status in various human disorders.

Guidelines for the diagnosis and treatment of cobalamin and folate disorders

The clinical picture is the most important factor in assessing the significance of test results assessing cobalamin status because there is no 'gold standard' test to define deficiency. Serum cobalamin currently remains the first-line test, with additional second-line plasma methylmalonic acid to help clarify uncertainties of underlying biochemical/functional deficiencies. Serum holotranscobalamin has the potential as a first-line test, but an indeterminate 'grey area' may still exist. Plasma homocysteine may be helpful as a second-line test, but is less specific than methylmalonic acid. The availability of these second-line tests is currently limited. Definitive cut-off points to define clinical and subclinical deficiency states are not possible, given the variety of methodologies used and technical issues, and local reference ranges should be established. In the presence of discordance between the test result and strong clinical features of deficiency, treatment should not be delayed to avoid neurological impairment. Treatment of cobalamin deficiency is recommended in line with the British National Formulary. Oral therapy may be suitable and acceptable provided appropriate doses are taken and compliance is not an issue. Serum folate offers equivalent diagnostic capability to red cell folate and is the first-line test of choice to assess folate status.

Evaluation of vitamin B12 monitoring in a veteran population on long-term, high-dose metformin therapy

BACKGROUND

Metformin can result in vitamin B(12) deficiency, potentially leading to complications such as neuropathy. Annual monitoring of vitamin B(12) has been suggested; however, it is unknown whether current practice reflects this recommendation.

OBJECTIVE

To identify vitamin B(12) monitoring patterns in patients on long-term, high-dose metformin. Secondary objective was to determine the frequency of new vitamin B(12) deficiency, anemia, and neuropathy documented after initiation of high-dose metformin.

METHODS

Electronic medical records of veterans treated at the Veterans Affairs Maryland Healthcare System with high-dose metformin (≥2000 mg/day) as of November 1, 2010, were reviewed. Data regarding metformin treatment, vitamin B(12) measurements, and documentation of vitamin B(12) deficiency, cyanocobalamin supplementation, anemia, and neuropathy were collected. Subjects treated with metformin for less than 1 year or those with documented peripheral neuropathy, megaloblastic anemia, vitamin B(12) deficiency, or a condition associated with vitamin B(12) malabsorption prior to metformin initiation were excluded.

RESULTS

Subjects (N = 235) had a mean metformin dose of 2050 mg/day and mean duration of treatment of 5.2 years. Sixty percent did not have vitamin B(12) measured. Of subjects receiving metformin for 10 years or more, nearly half (46%) never had vitamin B(12) measured. New documentation of vitamin B(12) deficiency or cyanocobalamin supplementation was found in 5.5% of the population, and anemia was found in 12%. Of the 14% with new neuropathy, 42% did not have vitamin B(12) measured.

CONCLUSIONS

Vitamin B(12) was not routinely monitored in patients on high-dose metformin, even in those at highest risk (≥10 years of therapy), or in those with potential manifestations of vitamin B(12) deficiency (neuropathy). Cases of vitamin B(12) deficiency and resulting anemia or neuropathy may be undiagnosed and untreated because of lack of monitoring. Prospective studies examining the effect of increased vitamin B(12) monitoring on identification and treatment of vitamin B(12) deficiency in patients on metformin are warranted.

Understanding Vitamin B12

Vitamin B12 (B12) is essential in activating folate needed in DNA synthesis. Inadequate intake results in the impairment of nerve transmission and inadequate synthesis of erythrocytes and other hematological cells. Two separate mechanisms of B12 absorption exist, a receptor-mediated endocytosis that occurs in the distal ileum and the mass-action pharmacologic mechanism. The recommended dietary allowance for B12 for adults issued by the Institute of Medicine is 2.4 µg/d. B12 is only found in meats and other foods of animal origin. B12 deficiency is widespread. Two main causes of deficiency include inadequate absorption and intake. Elderly and vegetarians are at highest risk for deficiency. Prevalence of deficiency ranges from 7% of the US population 3 years and older to 90% among vegans. The best way to assess deficiency is by using methylmalonic acid. Populations at risk could benefit from using B12 supplements and from fortification of flour.

Oral vitamin B12 replacement: an effective treatment for vitamin B12 deficiency after total gastrectomy in gastric cancer patients

BACKGROUND

Vitamin B12 deficiency is a common long-term sequelae after total gastrectomy. Intramuscular injection of vitamin B12 is the only known treatment. We investigated the efficacy and safety of oral vitamin B12 replacement for gastric cancer patients with vitamin B12 deficiency after total gastrectomy.

METHODS

We performed a single-arm, open-label, fixed-drug dosage, prospective study (NCT00699478) involving gastric cancer patients who underwent total gastrectomy. Vitamin B12-deficient (<200 pg/ml) patients (n = 30) received daily oral vitamin B12 (dosage: 1500 μg mecobalamin) administration for 3 months. The primary outcome measurement was serum vitamin B12. The secondary outcome measurements were improvement of neurologic symptoms and hematologic findings (serum folate, homocysteine, ferritin, iron, total iron binding capacity, transferrin, and mean corpuscular volume). For comparison, another group of vitamin B12 deficient patients (n = 30) received intramuscular vitamin B12 injections (dosage: 1000 μg cyanocobalamin) weekly for 5 weeks and monthly thereafter for a total of 3 months in a separate study period.

RESULTS

In both groups, mean serum vitamin B12 increased after 30 days of treatment and was maintained up to 90 days. No adverse effects related to oral or intramuscular vitamin B12 replacements were noted. Both groups showed decreased homocysteine levels. Before treatment, 29 patients in the oral vitamin B12 group had neurologic symptoms related to vitamin B12 deficiency. After oral vitamin B12 treatment, 28 patients experienced symptom relief, and 16 patients were symptom free.

CONCLUSIONS

Oral vitamin B12 replacement is an effective and safe treatment for vitamin B12 deficiency in gastric cancer patients after total gastrectomy.

Characteristics of anemia in elderly: a hospital based study in South India

Anemia is a common concern in older people and can have significant morbidity and mortality. Because anemia is a sign, not a diagnosis, an evaluation is almost always warranted to identify the underlying cause. The purpose of this study was to study the clinical profile of elderly patients with anemia and to study characteristics of hematological types of anemia in such patients as well as the closest possible etiological profile. Hundred patients above the age of 60 years were included in the study. Clinical profile with laboratory studies of Hemoglobin and diagnostic tests to fix the etiology. Majority of patients had normocytic blood picture. Renal failure was the most common underlying chronic disease. Significant number of patients were on non steroidal anti-inflammatory drugs which could contribute to the anaemia. 14% of the patients had an underlying malignancy. 73.3% of the patients in the microcytic group had an underlying GI lesion on endoscopy. Identifying anemia as an important aspect of a comprehensive geriatric assessment is absolutely essential further to clinical detection. Confirming the type of anemia is critical to direct the investigation for profiling the etiology since it is well known that the treatment of anemia goes a long way in improving the overall outcome and quality of life.

Nutritional management after Roux-en-Y gastric bypass

Changes in the anatomy and function of the gastrointestinal tract after bariatric surgery markedly change patients' eating patterns. Malnutrition is a significant risk associated with all bariatric procedures, which can lead to dangerous nutritional deficiencies. However, if correct patient selection is conducted and if patients receive thorough preoperative nutrition education and postoperative nutritional follow-up, these deficiencies are largely preventable. Nurses are important members of the multidisciplinary team; assisting in patient selection, providing hands-on care, and educating the patient on the surgical process and post-operative dietary restrictions. It is critical for nurses to understand immediate and projected nutritional consequences of surgery, in order to monitor the patient for diet tolerance and nutrient deficiency symptoms, to encourage dietary compliance, and to reinforce the long-term dietary restrictions. With appropriate supplementation and patient compliance, all nutritional deficiencies can be avoided or corrected.

Neurologic presentations of nutritional deficiencies

Optimal functioning of the central and peripheral nervous system is dependent on a constant supply of appropriate nutrients. The first section of this review discusses neurologic manifestations related to deficiency of key nutrients such as vitamin B(12), folate, copper, vitamin E, thiamine, and others. The second section addresses neurologic complications related to bariatric surgery. The third sections includes neurologic presentations caused by nutrient deficiencies in the setting of alcoholism. The concluding section addresses neurologic deficiency diseases that have a geographic predilection.

Vitamin B12 deficiency in hypersecretors during long-term acid suppression with proton pump inhibitors

BACKGROUND

Proton pump inhibitors (PPIs) may cause cyanocobalamin (vitamin B12) malabsorption, but measuring serum B12 alone may underestimate the prevalence. However, B12 deficiency elevates methylmalonic acid and homocysteine, both additional markers of B12 deficiency.

AIM

To determine the true prevalence of B12 deficiency and whether acid suppression by PPI caused it.

METHODS

Sixty-one acid hypersecretors (basal acid output >15 mmol/h), 46 with gastrinoma [Zollinger-Ellison (ZE) syndrome] and 15 without [acid hypersecretor without gastrinoma (pseudo-ZE)], were treated with lansoprazole to determine its long-term (up to 18 years) pharmacological and clinical efficacy and safety, particularly as regards malabsorption of B12.

RESULTS

Of 61 patients, six (10%) had low serum B12. Additional tests uncovered B12 deficiency in 13 (31%) of 41 still-available patients, despite normal serum B12. B12 replacement reduced elevated homocysteine and methylmalonic acid, supporting the diagnosis. Also, measuring both basal and stimulated gastric secretion, we found that acid suppression was neither prolonged nor profound enough to explain the B12 deficiency.

CONCLUSIONS

In long-term recipients of PPIs, B12 deficiency was more frequent (29%) than detected by measuring only serum B12, and there was not enough acid suppression to explain this deficiency.

Clinical management after bariatric surgery: value of a multidisciplinary approach

Comprehensive and collaborative longitudinal care is essential for optimal outcomes after bariatric surgery. This approach is important to manage the many potential surgical and medical comorbidities in patients who undergo bariatric surgery. Medical management programs require prompt and often frequent adjustment as the nutritional program changes and as weight loss occurs. Familiarity with the recommended nutritional program, monitoring and treatment of potential vitamin and mineral deficiencies, effects of weight loss on medical comorbid conditions, and common postoperative surgical issues should allow clinicians to provide excellent care. Patients must understand the importance of regularly scheduled medical follow-up to minimize potentially serious medical and surgical complications. Because the long-term success of bariatric surgery relies on patients' ability to make sustained lifestyle changes in nutrition and physical activity, we highlight the role of these 2 modalities in their overall care. Our guidelines are based on clinical studies, when available, combined with our extensive clinical experience. We present our multidisciplinary approach to postoperative care that is provided after bariatric surgery and that builds on our presurgical evaluation.

Nutritional concerns related to Roux-en-Y gastric bypass: what every clinician needs to know

Weight loss surgery, particularly the Roux-en-Y gastric bypass (REYGB), has become a popular treatment strategy for obesity. Often the only measure of success is the amount of weight lost following surgery. Unfortunately the nutritional adequacy of the postoperative diet has frequently been overlooked, and in the months to years that follow, nutritional deficiencies have become apparent, including protein-calorie malnutrition and various vitamin and mineral deficiencies contributing to medical illnesses and limiting optimal health. Therefore, patients require close monitoring following REYGB, with special regard to the rapidity of weight loss and vigilant screening for signs and symptoms of subclinical and clinical nutritional deficiencies. Several specific nutrients require close surveillance postoperatively to prevent life-threatening complications related to deficient states. This article addresses nutritional concerns associated with REYGB with fastidious focus on recognition and treatment of the nutritional deficiencies and promotion of nutritional health following REYGB. Recommendations regarding nutritional intake following REYGB are based on available scientific data, albeit limited. In cases where data do not exist, expert or consensus opinion is provided and recommendations for future research are given. Ultimately, clinical application of this information will contribute to the prevention of nutrition-related illness associated with REYGB.

Vitamin supplementation: what the gastroenterologist needs to know

BACKGROUND

The vitamin business is a multimillion dollar industry. Aggressive marketing strategies are used to make claims for the health benefits of these products. Observational studies suggest that people who consume vitamin supplements decrease their risks for cancer, cardiovascular disease, and gastrointestinal disease. What is the evidence for these claims, and as a prescribing gastroenterologist, is there a scientific basis for vitamin supplementation?

METHODS

A narrative review focusing on randomized controlled trials, where available, plus observational studies obtained from personal files, "on-line" searches, and references in reviewed articles.

RESULTS

From the perspective of a gastroenterologist, there is strong evidence to recommend B12 supplementation in gastric and intestinal disease, as well as pernicious anemia. There exists moderate evidence to support B12 supplements in pancreatic disease. Vitamin D and calcium supplementation are recommended for persons with disorders of malabsorption, cholestasis, and illnesses requiring chronic steroids. Only observational studies suggest a correlation between vitamin D/calcium and decreased colorectal adenoma recurrence. Although folic acid supplementation is beneficial in persons on medications such as methotrexate and sulfasalazine, studies are contradictory with regard to folic acid and colon cancer prevention. Overall, antioxidants have not been proven to decrease the risk for colorectal adenoma, gastric cancer, or esophageal cancer.

CONCLUSIONS

Observational studies do not correlate with randomized clinical trials; therefore, few definitive recommendations can be made. Vitamin supplements are appropriate for recognized deficiencies; however, there is a lack of evidence to support their effects in the prevention of chronic disease.

Pregnancy following bariatric surgery

Gastric bypass surgery for morbid obesity is considered an appropriate intervention when other weight-loss measures have proven unsuccessful. Weight loss often brings about improvement in overall health by lessening the effects of obesity-related comorbidities such as chronic hypertension and diabetes. In fact, the ability to become pregnant is enhanced, as weight loss often allows for a normalization of sex hormones. However, the nutrition challenges brought about by the surgery may have a profound impact on maternal health and pregnancy outcome. Surgical procedures for morbid obesity may be classified according to the digestive aftereffects brought about by the particular procedure. These categories include the "restrictive" procedures, "restrictive-malabsorptive" procedures, and the less common "malabsorptive" procedures. Deficiencies in iron, vitamin B12, folate, and calcium can result in maternal complications, such as severe anemia, and in fetal complications, such as neural tube defect, intrauterine growth restriction, and failure to thrive. Nutrient supplementation following bariatric surgery and close supervision before, during, and after pregnancy can help prevent nutrition-related complications and improve maternal and fetal health.

Serum selenium is associated with plasma homocysteine concentrations in elderly humans

Low selenium levels in humans have been associated with several pathologies; however, an earlier animal investigation found a direct association between Se intake and total plasma homocysteine (tHcy) concentrations. To date, the importance of serum selenium levels in association with tHcy in humans has not been determined. We evaluated the cross-sectional association of blood selenium concentrations with plasma tHcy and other determinants of this cardiovascular disease risk factor. We estimated protein intake and measured the blood status of selenium, tHcy, and several other related factors in serum such as folate, vitamin B-12, and creatinine. Serum selenium was inversely associated with tHcy, explaining 5.8% of tHcy variance with respect to 2.2% accounted for by serum folate. Furthermore, there was a 63% decreased risk of higher tHcy concentrations (>14 micro mol/L) for subjects with serum selenium in the highest tertile (P = 0.013). We also found an inverse association of protein intake with tHcy in men (beta = -0.144; P = 0.036), which disappeared after controlling for serum Se concentrations (beta = -0.055; P = 0.003). In conclusion, selenium should be considered as a potential factor to lower tHcy. In addition, the described association between protein intake and homocysteine levels could be mediated by this trace element.

Dietary Pattern Is Associated with Homocysteine and B Vitamin Status in an Urban Chinese Population

To identify existing dietary patterns and examine associations between these patterns and plasma homocysteine and B vitamin concentrations in an urban Chinese population living in Beijing (n = 119), dietary information was collected with a food frequency questionnaire designed for this population. Plasma homocysteine and B vitamin concentrations were examined. Food group variables, expressed as percentages of total energy intake, were entered into cluster analysis to define three distinct dietary pattern groups. The prevalence of high homocysteine (>11 micromol/L for women and 12 micromol/L for men), was 31.9%; of low folate (<6.8 nmol/L), 36.2%; of low vitamin B-12 (<221 pmol/L), 36.9%; and of low vitamin B-6 (<30 nmol/L), 16.0%. The three dietary patterns derived were defined by relatively greater intake of 1) fruit and milk, 2) red meat and 3) refined cereals. More than 40% of subjects in the refined cereals group had high plasma homocysteine and low plasma folate concentrations, and 67% had low plasma vitamin B-12 concentrations. Those following the refined cereals pattern were 4 and 5.2 times more likely to have high homocysteine and low vitamin B-12 concentrations, respectively, relative to the fruit and milk dietary pattern group (P < 0.01), after adjustment for potential confounders. High intake of refined cereals was associated with low B vitamin and high homocysteine concentrations, whereas the pattern high in fruit and milk was associated with the lowest homocysteine. Dietary patterns appear to play an important role in the micronutrient and homocysteine status of these Chinese adults.

Epidemiology of anemia in the elderly: information on diagnostic evaluation

A rise in the aging population has been predicted, and, as a result, it is expected that the incidence of age-related health conditions will also increase. Although common in the elderly, anemia is often mild and asymptomatic and rarely requires hospitalization. However, untreated anemia can be detrimental, because it is associated with increased mortality, poor health, fatigue, and functional dependence and can lead to cardiovascular and neurological complications. Several factors have been suggested to cause anemia in this population, for example, blood loss or chronic disease. In some cases, the cause is unknown. It has been suggested that this is a result of the presence of comorbid conditions that can mask the symptoms of anemia. Therefore, appropriate diagnosis and management strategies of anemia in the elderly need to be identified, particularly because anemia may indicate the presence of other serious diseases.

Hyperhomocysteinemia and vitamin B-12 deficiency in elderly using Title IIIc nutrition services

BACKGROUND

The effect of the folate food fortification program on the prevalence of hyperhomocysteinemia in the older population with coexisting vitamin B-12 deficiency is not known.

OBJECTIVE

The objective was to determine the prevalence of hyperhomocysteinemia and vitamin B-12 deficiency in elderly who were using Title IIIc nutrition services, after folate food fortification in the United States.

DESIGN

Demographic, nutritional, cognitive, routine diagnostic, and serum methylmalonic acid (MMA) and total homocysteine (tHcy) tests were performed in a convenience sample of 103 elderly enrolled in nutrition service programs in rural northeast Georgia. A subgroup (n = 27) was treated with vitamin B-12, 2.5 mg, and a multivitamin with 400 micro g folic acid, 2 mg vitamin B-6, and 27 mg ferrous fumarate.

RESULTS

The total cohort included 103 participants (+/- SD age: 76.4 +/- 8.1; 80% female; 68% white, 32% African American). Vitamin B-12 deficiency (serum vitamin B-12 < 258 pmol/L and MMA > 271 nmol/L) was present in 23%. Mean serum folate was high, 39.3 nmol/L, and no subject had serum folate < 6.8 nmol/L. Mean tHcy was 17.6 +/- 7.2 micro mol/L in vitamin B-12-deficient subjects and 10.8 +/- 3.6 micro mol/L in those who were nondeficient. Determinants of high tHcy were vitamin B-12 deficiency, high serum creatinine, and low red blood cell folate. Those with vitamin B-12 deficiency were more likely to have poor cognition (58% compared with 20%, P < 0.001) and anemia (38% compared with 18%, P = 0.042). High-dose oral B-12 therapy lowered mean MMA and tHcy by 49% and 32%, respectively.

CONCLUSION

Vitamin B-12 deficiency was prevalent and was associated with poor cognition, anemia, and hyperhomocysteinemia.

Neurologic manifestations of gastrointestinal disease

Although previously considered rare, neurologic manifestations of gastrointestinal diseases are increasingly recognized. Understanding of Whipple disease and gluten sensitivity is in transition and these conditions are becoming the province of neurologists. Recent improvements in diagnostic testing have improved our understanding and case finding for vitamin B12 deficiency. Many patients with these conditions present with neurologic manifestations alone. Therefore, these conditions are becoming the province of neurologists, and neurologic manifestations of gastrointestinal disease are becoming a more common part of neurologic practice.

[Protein-energy malnutrition in the gastrectomized patient]

BACKGROUND

Gastrectomy leads to nutritional consequences that although expected, are not usually measured due to methodological limitations.

AIM

To assess the protein-energy deficiency degrees estimated by isolated or combined indicators.

PATIENTS AND METHODS

There were studied 71 patients, who had undergone partial (n = 53) or total (n = 18) gastrectomy in the last 6-24 months (M1) or 24-60 months (M2). The dietary intake, body composition and biochemical data were estimated and compared between groups and moments.

RESULTS

The surgeries were undertaken after complications of peptic ulcer (68%) or due to gastric cancers (32%). Weight loss was referred by 70% of patients and higher (16 +/- 5 x 10 +/- 6 kg) in total gastrectomy group. The patients showed anthropometric deficits along with normal albumin and low energy intake, suggesting chronic-energy deficiency. Hematocrit, hemoglobin and iron showed the most prominent reductions. Anemia was installed earlier and worsened in the total gastrectomy group. Thus, when combining hemoglobin + albumin, + total lymphocyte count + arm circumference and subscapular skinfold, the protein-energy deficiency prevalence was higher and more severe than when hemoglobin was omitted. The protein-energy deficiency occurred earlier and it was more severe in total gastrectomy patients, while in partial gastrectomy the protein-energy deficiency increased in the late post-operative period.

CONCLUSION

The protein-energy deficiency resulted from gastrectomy is more marasmus-like coarsing with anemia, both installed earlier and severer in total gastrectomy than partial gastrectomy but ending up similarly at the late postoperatory.

Nutrition in gastroenterology and hepatology

Nutritional issues, sometimes obvious and sometimes not so obvious, confront the primary care practitioner on a daily basis. Understanding the multi-disciplinary nature of nutrition science and clinical nutrition and having a basic understanding of gastrointestinal tract digestive and absorptive physiology can only help sort out the many issues involved. The general practitioner needs a core understanding of the principles of nutrition assessment.

Nutritional deficiencies and blunted erythropoietin response as causes of the anemia of critical illness

PURPOSE

The purpose of this article was to determine the prevalence of iron, vitamin B12, and folate deficiency and to evaluate the erythropoietin (EPO) response to anemia in a cohort of long-term intensive care unit (ICU) patients.

MATERIALS AND METHODS

All patients admitted to three academic medical center multidisciplinary ICUs were screened for eligibility into a randomized trial of EPO for the treatment of ICU anemia. On their second or third ICU day, patients enrolled in this trial had EPO levels drawn and were screened for iron, B12, and folate deficiency. Weekly EPO levels were obtained throughout patients' ICU stay.

RESULTS

A total of 184 patients were screened for iron, B12, and folate deficiency. Sixteen patients (9%) were iron deficient by study criteria, 4 (2%) were B12 deficient, and 4 (2%) were folate deficient. Mean hemoglobin and reticulocyte percents of the remaining 160 patients were 10.3 +/- 1.2 g/dL and 1.66 +/- 1.09%, respectively. In most patients, serum iron and total iron binding capacity levels were very low, whereas ferritin levels were very high. Mean and median day 2 EPO levels were 35.2 +/- 35.6 mIU/mL and 22.7 mIU/mL, respectively (normal = 4.2-27.8). Serial EPO levels in most persistently anemic patients remained within the normal range.

CONCLUSIONS

In this cohort, screening for iron, B12, and folate deficiency identified potentially correctable abnormalities in more than 13% of patients and should be considered in those who are anticipated to have long ICU stays. Even at an early point of critical illness, most patients had iron studies consistent with anemia of chronic disease (ACD), as well as a blunted EPO response that may contribute to this ACD-like anemia of critical illness.

Elevated homocysteine levels with weight loss after Lap-Band surgery: higher folate and vitamin B12 levels required to maintain homocysteine level

OBJECTIVE

To investigate homocysteine levels and their relationship with serum folate and vitamin B12 concentrations with weight loss after the Lap-Band form of gastric restrictive surgery, with the view to minimizing risk.

METHODS

We measured levels of fasting plasma homocysteine (tHcy), folate (serum and RBC) and vitamin B12 in two groups. The study group was 293 consecutive patients at 12 (n=192) or 24 (n=101) months review after surgery. The controls were 244 consecutive patients presenting for this surgery.

RESULTS

The group losing weight had higher geometric mean tHcy levels: 10.4 (95% CI, 9.8-10.8) micromol/l compared with 9.2 (95% CI, 8.9-9.7) in controls (P<0.001). This occurred with higher folate levels and unchanged vitamin B12 levels. Levels of folate and B12 together explained 35% (r (2)) of the homocysteine variance in the weight loss group compared with only 9% (r (2)) in controls (P<0.001). Those taking regular multivitamin supplements had lower tHcy levels: 9.6 (9.1-10.0) micromol/l vs 12.3 (11.4-13.3) in those not taking supplements (P<0.001). A low normal plateau of tHcy levels occurred at levels of folate >15 ng/l and B12)600 ng/ml. A curvilinear relationship exists between these cofactors and tHcy levels, with the dose-response relationship shifted to the right in the weight loss group.

CONCLUSION

This study shows elevated tHcy levels with weight loss, without lower serum folate or vitamin B(12) levels. There is an altered dose-response relationship with higher serum B(12) and folate levels required to maintain recommended tHcy levels. Patients losing weight have significant health benefits; however, they may be at greater risk of vascular events or fetal abnormality in association with raised tHcy levels. Multivitamin supplementation is effective in lowering tHcy levels.