Laboratory evaluation for vitamin B12 deficiency: the case for cascade testing

Management and outcomes of catatonia: A prospective study in urban South Africa

Objectives

Rapid intervention for catatonia with benzodiazepines and electroconvulsive therapy can prevent fatal complications. We describe the management and treatment response of 44 patients with catatonia in a psychiatric unit in urban South Africa. The objective was to screen admissions for catatonia and investigate management, treatment response, and treatment outcomes.

Method

We used a prospective, descriptive, observational study design and collected data using a data collection sheet, the Bush Francis Catatonia Screening Instrument, the Bush Francis Catatonia Rating Scale, and the Diagnostic Statistical Manual-5 to assess catatonia in new admissions from September 2020 to August 2021.

Results

Of the 241 participants screened on admission, 44 (18.3% of 241) screened positive for catatonia on the Bush Francis Catatonia Screening Instrument, while 197 (81.7% of 241) did not. Thirty-eight (86.4% of 44) received lorazepam, seven (15.9%) received clonazepam, and two (4.6%) received diazepam, implying that three (6.8%) of the 44 participants with catatonia received more than one benzodiazepine sequentially. Ten (22.7% of 44) patients received electroconvulsive therapy. Seven of those treated with electroconvulsive therapy (15.9% of 44 and 70% of 10) responded well and were discharged, whereas 22 (50% of 44 and 64.7% of 34) of those given lorazepam were discharged. Patients treated with electroconvulsive therapy had a higher initial Bush Francis Catatonia Rating Scale score. One patient (2.3%) relapsed within 4 weeks of discharge. Twenty (45.5%) of the 44 patients with catatonia had low average iron levels, 14 (31.8%) had low vitamin B12, and 24 (54.6%) had high creatinine kinase.

Conclusion

Both lorazepam and electroconvulsive therapy were found to be effective treatments for catatonia with good response and outcomes. The length of hospital stay of patients with catatonia was similar to that of patients without catatonia. Treatment guidelines for catatonia need to include the role and timing of electroconvulsive therapy to augment current treatment protocols for the use of lorazepam.

Persistent elevation of plasma vitamin B12 is strongly associated with solid cancer

Elevated plasma vitamin B12 has been associated with solid cancers, based on a single B12 measurement. We evaluated the incidence of solid cancers following B12 measurement in patients with persistent elevated B12, compared to patients without elevated B12 and to patients with non-persistent elevated B12. The study population included patients with at least two plasma B12 measurements without already known elevated-B12-related causes. Patients with elevated plasma B12 (≥ 1000 ng/L) at first measurement (n = 344) were matched for age and sex with patients having 2 normal B12 measurements (< 1000 ng/L) (NN group, n = 344). The patients with elevated plasma B12 at first measurement were split into 2 groups, according to the presence (EE group, n = 144) or the absence (EN group, n = 200) of persistent elevated plasma B12 at second measurement. We compared the cancer-free survival during 60 months between the groups after adjustment for the other elevated-B12-related causes in a survival competing risk model. Compared to the NN group, a persistent elevated plasma B12 ≥ 1000 ng/mL was strongly associated with the occurrence of solid cancer (HR 5.90 [95% CI 2.79-12.45], p < 0.001), contrary to non-persistent plasma B12 elevation (p = 0.29). These results could help to select patients in whom the screening for solid cancers would be of interest.

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.

Nitrous oxide-induced demyelination: Clinical presentation, diagnosis and treatment recommendations

BACKGROUND

Recreational use of nitrous oxide (NO) in the general public has led to increasing reports of NO-induced demyelination (NOID). We describe the varying clinical presentations and pathophysiology, and offer a treatment paradigm.

METHODS

A literature search of MEDLINE and EMBASE resulted in 42 publications with 37 studies meeting the inclusion criteria, for a total of 51 patients. Our case series included 5 patients seen from 2014 to 2018 followed over 3-60 months.

RESULTS

Those with sensory symptoms and subjective weakness were categorized as having "mild" symptoms (25%). Symptoms indicating involvement outside the dorsal columns such as observer-graded weakness were categorized as "moderate" (61%). Patients with the aforementioned plus cognitive effects were categorized as "severe" (12%). There was no dose-dependent relationship between the amount of NO used and clinical impairment. There was a trend between the severity of neurologic impairment and serum levels of B12. Two patients were noncompliant. One initiated only oral therapy and did not improve. One received injections a month apart and worsened.

CONCLUSIONS

Patients with NOID tend to have worse symptoms when presenting with lower serum vitamin B12 levels and have good recovery rates when treated with intramuscular B12 and oral supplementation.

Strength of the Association of Elevated Vitamin B12 and Solid Cancers: An Adjusted Case-Control Study

The association between elevated plasma vitamin B12 (B12) level and solid cancers has been documented by two national registries. However, their design did not allow for the adjustment for other conditions associated with elevated B12. The objectives of this study were to confirm this association after the adjustment for all causes of elevated B12, and to study the variations according to the increasing B12 level, the type of cancers, and the presence of metastases. We compared 785 patients with B12 ≥ 1000 ng/L with 785 controls matched for sex and age with B12 < 1000 ng/L. Analyses were adjusted for the causes of elevated B12: myeloid blood malignancies, acute or chronic liver diseases, chronic kidney failure, autoimmune or inflammatory diseases, and excessive B12 supplementation. A B12 ≥ 1000 ng/L was associated with the presence of solid cancer without metastases (OR 1.96 [95%CI: 1.18 to 3.25]) and with metastases (OR 4.21 [95%CI: 2.67 to 6.64]) after adjustment for all elevated B12-related causes. The strength of the association rose with the increasing B12 level, in particular in cases of metastases. No association between liver cancers and elevated B12 level was found after adjustment for chronic liver diseases. In conclusion, unexplained elevated B12 levels should be examined as a possible marker of solid cancer.

Methylmalonic acid and vitamin B12 in patients with heart failure

OBJECTIVE

Vitamin B12 deficiency among patients with heart failure (HF) may have been underestimated. High serum levels of methylmalonic acid (MMA) have been identified in several studies as an early indicator of vitamin B12 deficiency. Furthermore, MMA seems to constitute a biomarker of oxidative stress and mitochondrial dysfunction. There are scarce data regarding vitamin B12 and MMA in patients with HF. The aim of this study was to investigate vitamin B12 and MMA serum levels in patients with HF.

METHODS

One hundred five consecutive patients admitted to our hospital with symptoms and signs of acute decompensated HF were included in the study. Demographic and clinical characteristics as well as comorbidities and medical treatment before hospital admission were recorded. Transthoracic echocardiography was performed in all patients. Blood samples were collected during the first 24 hours of hospitalization and measured for complete blood count, biochemical profile, vitamin B12, N-terminal prohormone of brain natriuretic peptide, and MMA levels. Finally, 51 healthy individuals constituted the control group.

RESULTS

A total of 43.8% of patients with HF had elevated MMA levels, but only 10.5% had overt vitamin B12 deficiency, defined as serum cobalamin levels below 189 pg/ml. Mean MMA level was higher in patients with HF than in controls (33.0 ± 9.6 vs. 19.3 ± 6.3 ng/ml; p < 0.001). This difference remained significant when adjusted for age, sex, vitamin B12, and folate serum levels and kidney function (B = 14.7 (9.6-19.7); p < 0.001). MMA levels were higher in patients with acutely decompensated chronic HF than in those with newly diagnosed acute HF (34.7 ± 10.5 vs. 30.7 ± 7.8 ng/ml; p = 0.036). Correlation analysis revealed significantly negative correlation between MMA and vitamin B12 levels only in patients without comorbidities.

CONCLUSION

Patients with HF have elevated MMA levels, independent of age, gender, HF category, or comorbidities, possibly indicating subclinical vitamin B12 deficiency. Further research is needed to investigate subclinical vitamin B12 deficiency in patients with HF and/or to clarify whether MMA constitutes a biomarker of oxidative stress.

Relationship between cobalamin and folate deficiencies and anemia in dogs

Background

Megaloblastic, nonregenerative anemia is a well‐known consequence of cobalamin or folate deficiencies in humans but is not recognized in hypocobalaminemic or hypofolatemic dogs. Establishment of relationships between hypocobalaminemia or hypofolatemia and hematologic disease would encourage vitamin B testing, and potentially supplementation, in anemic dogs.

Objectives

To determine the prevalence of anemia in hypocobalaminemic or hypofolatemic dogs and to report the prevalence of hypocobalaminemia and hypofolatemia and nonregenerative anemia, macrocytosis, and anisocytosis in anemic dogs.

Animals

One hundred and fourteen client‐owned dogs with known serum cobalamin and folate concentrations and CBCs and 42 client‐owned anemic dogs.

Methods

Retrospective comparison of anemia prevalence in hypocobalaminemic or hypofolatemic and normocobalaminemic or normofolatemic dogs was performed. Prospective measurement of erythrocyte variables and cobalamin and folate concentrations in anemic dogs was carried out; relationships among hypocobalaminemia and regenerative status, mean corpuscular volume, and red cell distribution width were evaluated.

Results

Significant differences in prevalence of anemia between hypocobalaminemic (36%) and normocobalaminemic dogs (26%; P = .23) or between hypofolatemic (31%) and normofolatemic dogs (30%; P = .99) were not detected. Between hypocobalaminemic and normocobalaminemic dogs, no significant differences in prevalence of nonregenerative anemia (69% vs 63%; P = .65), macrocytosis (17% vs 0%; P = .53), or anisocytosis (28% vs 0%; P = .14) were detected. Anemic dogs had high prevalence of vitamin B deficiencies (nonregenerative: 64% hypocobalaminemic, 18% hypofolatemic; regenerative: 57% hypocobalaminemic, 21% hypofolatemic).

Conclusions and Clinical Importance

The association between cobalamin and folate deficiencies and macrocytic, nonregenerative anemia established in humans is not routinely present in dogs.

Improved testing for vitamin B12 deficiency: correcting MMA for eGFR reduces the number of patients classified as vitamin B12 deficient

Background Methylmalonic acid (MMA) can detect functional vitamin B₁₂ deficiencies as it accumulates early when intracellular deficits arise. However, impaired clearance of MMA from blood due to decreased glomerular filtration rate (eGFR) also results in elevated plasma MMA concentrations. Alternative to clinical trials, a data mining approach was chosen to quantify and compensate for the effect of decreased eGFR on MMA concentration. Methods Comprehensive data on patient's vitamin B₁₂, eGFR and MMA concentrations were collected ( n = 2906). The relationship between vitamin B₁₂, renal function (eGFR) and MMA was modelled using weighted multiple linear regression. The obtained model was used to estimate the influence of decreased eGFR on MMA. Clinical impact was examined by comparing the number of patients labelled vitamin B₁₂ deficient with and without adjustment in MMA. Results Adjusting measured MMA concentrations for eGFR in the group of patients with low-normal vitamin B₁₂ concentrations (90-300 pmol/L) showed that the use of unadjusted MMA concentrations overestimates vitamin B₁₂ deficiency by 40%. Conclusions Through a data mining approach, the influence of eGFR on the relation between MMA and vitamin B₁₂ can be quantified and used to correct the measured MMA concentration for decreased eGFR. Especially in the elderly, eGFR-based correction of MMA may prevent over-diagnosis of vitamin B₁₂ deficiency and corresponding treatment.

Considerations for Secondary Prevention of Nutritional Deficiencies in High-Risk Groups in High-Income Countries

Surveys in high-income countries show that inadequacies and deficiencies can be common for some nutrients, particularly in vulnerable subgroups of the population. Inadequate intakes, high requirements for rapid growth and development, or age- or disease-related impairments in nutrient intake, digestion, absorption, or increased nutrient losses can lead to micronutrient deficiencies. The consequent subclinical conditions are difficult to recognize if not screened for and often go unnoticed. Nutrient deficiencies can be persistent despite primary nutrition interventions that are aimed at improving dietary intakes. Secondary prevention that targets groups at high risk of inadequacy or deficiency, such as in the primary care setting, can be a useful complementary approach to address persistent nutritional gaps. However, this strategy is often underestimated and overlooked as potentially cost-effective means to prevent future health care costs and to improve the health and quality of life of individuals. In this paper, the authors discuss key appraisal criteria to consider when evaluating the benefits and disadvantages of a secondary prevention of nutrient deficiencies through screening.

An observational study of vitamin b12 levels and peripheral neuropathy profile in patients of diabetes mellitus on metformin therapy

METHODS

A descriptive, observational study was completed in a tertiary care hospital between November 2014 and March 2016. Fifty consecutive patients of Type 2-Diabetes Mellitus who had been on metformin therapy for at least three months were included in our study. Several Parameters were compared with vitamin B12 levels and severity of peripheral neuropathy (using Toronto Clinical Scoring System (TCSS) and Nerve Conduction Velocity). These included the duration of diabetes, duration of metformin usage, dietary history, and HbA1c levels. Definite B12 deficiency was defined as B12<150pg/ml and possible B12 deficiency as <220pg/ml.

RESULTS

In our study, we found a negative correlation between duration of metformin use and Vitamin B12 levels(r=-0.40). The mean Vitamin B12 levels seen in our study was 212.3pg/mL. There is a positive correlation between the duration of metformin therapy and peripheral neuropathy (r=0.40). The mean TCSS score was 6.8. The percentage of patients with mild neuropathy was 28%, with moderate neuropathy was 20% and severe neuropathy in 12% of the patients. The average duration of metformin use in patients without peripheral neuropathy was 5.5yrs whereas the average length of metformin use in patients with peripheral neuropathy was 10.4 yrs.

CONCLUSION

Patients on long-term metformin therapy are at a high risk for Vitamin B12 deficiency and peripheral neuropathy. Interval Screening for peripheral neuropathy is recommended for patients on metformin even if Vitamin B12 levels appear to be normal.

Nutrition Recommendations in Elderly and Aging

Maintaining optimal health and well-being in the older adult requires understanding of how physiologic changes influence nutritional status, familiarity with the available validated tools to assess status, identification of factors predisposing older adults to malnutrition, and evidence-based practice regarding the nutritional needs of this age group. Evidence-based guidance on these core practice components is provided to the clinician in this article.

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.

The hematological effects of nitrous oxide anesthesia in pediatric patients

BACKGROUND

Prolonged administration of nitrous oxide causes an increase in plasma homocysteine in children via vitamin B12 inactivation. However, it is unclear whether nitrous oxide doses used in clinical practice cause adverse hematological effects in pediatric patients.

METHODS

This retrospective study included 54 pediatric patients undergoing elective spinal surgery: 41 received nitrous oxide throughout anesthesia (maintenance group), 9 received nitrous oxide for induction and/or emergence (induction/emergence group), and 4 did not receive nitrous oxide (nitrous oxide-free group). Complete blood counts obtained before and up to 4 days after surgery were assessed for anemia, macrocytosis/microcytosis, anisocytosis, hyperchromatosis/hypochromatosis, thrombocytopenia, and leukopenia. The change (Δ) from preoperative to the highest postoperative value was calculated for mean corpuscular volume (MCV) and red cell distribution width (RDW).

RESULTS

No pancytopenia was present in any patient after surgery. All patients had postoperative anemia, and none had macrocytosis. Postoperative MCV (mean [99% confidence interval]) peaked at 86 fL (85-88 fL), 85 fL (81-89 fL), and 88 fL (80-96 fL) and postoperative RDW at 13.2% (12.8-13.5%), 13.3% (12.7-13.8%), and 13.0% (11.4-14.6%) for the maintenance group, the induction/emergence group, and the nitrous oxide-free group. Two patients in the maintenance group (5%) developed anisocytosis (RDW >14.6%), but none in the induction/emergence group or in the nitrous oxide-free group (P = 0.43). Both ΔMCV (P = 0.52) and ΔRDW (P = 0.16) were similar across all groups.

CONCLUSIONS

Nitrous oxide exposure for up to 8 hours is not associated with megaloblastic anemia in pediatric patients undergoing major spinal surgery.