Vitamin B12 deficiency in children and adolescents

Folic acid and autism: updated evidences

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition that impairs communication, socialization, and behavior. The association of ASD with folic acid has been investigated due to the importance of this vitamin for neurological health. This study is an update of the publication 'Folic acid and autism: What do we know?' and aims to systematically review studies examining the relationship between folic acid and ASD. The search resulted in 2,389 studies on folic acid and ASD, which were selected by two reviewers based on their titles and abstracts. Studies meeting the inclusion criteria were fully read. The 52 included studies involved 10,429 individuals diagnosed with ASD and assessed the intake of vitamin B6, folic acid, and vitamin B12; serum levels of these vitamins, homocysteine, and methionine; therapeutic interventions using folic acid; and the association between maternal exposure to this vitamin and the risk of ASD. The evidence of insufficient folic acid intake in most individuals with ASD remains consistent in this update. No association was found between maternal exposure to folic acid and the risk of ASD in their children. Despite observed improvements in communication, socialization, and behavior in individuals with ASD following folic acid interventions, it is crucial to consider the individuality and complexity of ASD. Given the relevance of the topic, there remains a need for more high-quality research and clinical trials characterized by rigorous methodological designs.

Vitamin deficiencies in children: Lessons from clinical and neuroimaging findings

BACKGROUND AND AIMS

Water-soluble vitamins play an essential coenzyme role in the nervous system. Acquired vitamin deficiencies are easily treatable, however, without treatment, they can lead to irreversible complications. This study aimed to provide clinical, laboratory parameters and neuroimaging data on vitamin deficiencies in an attempt to facilitate early diagnosis and prompt supplementation.

METHODS

From July 1998 to July 2023, patients at Necker-Enfants-Malades Hospital presenting with acute neurological symptoms attributed to acquired vitamin deficiency were included. Clinical data were extracted from Dr Warehouse database. Neuroimaging, biochemical and electrophysiological data were reviewed.

RESULTS

Patients with vitamin B1 deficiency exhibited abnormal eye movements (n = 4/4), fluctuations in consciousness (n = 3/4), and ataxia (n = 3/4). Brain MRI showed alterations of fourth ventricle region (n = 4/4), periaqueductal region (n = 4/4), tectum (n = 3/4), and median thalami (n = 3/4). Patients with vitamin B2 deficiency presented with early onset hypotonia (n = 3/4), hyperlactatemia (n = 4/4), and hyperammonemia (n = 4/4). Plasma acylcarnitines revealed a multiple acyl-coA dehydrogenase deficiency-like profile (n = 4/4). In vitamin B12 deficiency, young children presented with developmental delay (n = 7/7) and older children with proprioceptive ataxia (n = 3/3). Brain MRI revealed atrophy (n = 7/7) and spinal MRI hyperintensity in posterior cervical columns (n = 3/3). Metabolic findings showed elevated methylmalonic acid (n = 6/7) and hyperhomocysteinemia (n = 6/7). Patients with vitamin C deficiency exhibited gait disturbances and muscle weakness (n = 2/2).

CONCLUSIONS

Acquired vitamin deficiencies may display reversible clinical symptoms mimicking inherited metabolic disorders. Some situations raise suspicion for diagnosis: concordant clinical presentation, suggestive neuroimaging findings, and/or biochemical evidence. Any acute neurological condition should be treated without waiting for definitive biochemical confirmation.

Evaluation of Neurodevelopmental Screening Test Scores in Children with Vitamin B12 Deficiency

INTRODUCTION

 Vitamin B12 deficiency can lead to hematological findings, neurological symptoms, and neurodevelopmental delay. The aim of this study was to investigate the impact of vitamin B12 deficiency on the neurodevelopment of children.

MATERIALS AND METHODS

 This study included 89 children aged between 6 and 24 months without any complaints; 44 of these were evaluated in the study group (serum vitamin B12 <300 pg/mL) and 45 in the control group (serum vitamin B12 ≥300 pg/mL). Denver Developmental Screening Test II (DDST-II) and the Social Communication Area Screening Test (SCAST) were evaluated in each participant.

RESULTS

 The mean vitamin B12 level in the study group was 206.11 ± 9.1 pg/mL, and in the control group, it was 540.65 ± 24.1 pg/mL. When DDST-II results were analyzed, the rate of getting suspicious and abnormal results in the study group was significantly higher compared with the control group (p = 0.001). The rate of the "risky" SCAST results of the cases was found to be statistically significantly higher in the study group than in the control group (p = 0.003). Vitamin B12 values of patients with suspicious or abnormal DDST-II results and with risky SCAST results were found to be statistically significantly lower than those with normal neurodevelopmental screening tests results (p = 0.001 and p = 0.001, respectively).

CONCLUSION

 Vitamin B12 deficiency can lead to neurodevelopmental delay in children, even in the absence of neurological and hematological symptoms or complaints, which highlights the importance of early detection and intervention of vitamin B12 deficiency.

Dietary intake, nutritional adequacy and food sources of vitamins involved in the methionine-methylation cycle from Spanish children aged one to <10 years: results from the EsNuPI study

Background

Methionine-methylation cycle and the derived critical functions during infancy are key regulated by folates, vitamins B12, and B6. At present in Spain, there is an absence of studies that assess the intakes and dietary sources of total folates and B12 by children consuming all types of milks and those regularly consuming adapted milk formulas. Thus, our aim was to evaluate folates intakes alongside with vitamins B6 and B12 while describing their major dietary contributors in Spanish children aged one to <10 years.

Methods

A total of 1,448 children aged between 1 and 10 years (49.7% girls and 50.3% boys) from the EsNuPI, a prospective cross-sectional study, were allocated into two cohorts: one Spanish Reference Cohort (SRS) of the general population (n = 707), and another including children consuming adapted milks called Adapted Milk Consumers Cohort (AMS) (n = 741) completed two 24 h dietary recalls used to estimate their nutrient intakes and to compare them to the European Food Safety Authority (EFSA) Population Reference Intakes.

Results

The median intake of vitamin B6 was 1.35 (1.06-1.70) mg/day in the SRS and 1.45 (1.17-1.79) mg/day in the AMS, being significantly higher in the AMS for all age-groups. Prevalence of adequacy for vitamin B6 in the SRS and AMS was 97.7 and 98.7%, respectively. Total folates intakes in the AMS were significantly higher (p ≤ 0.001) in all age groups than in the SRS, independently of age. In addition, the prevalence of adequacy for folates intakes in all groups was more than 60%. Vitamin B12 intake increased with age independently of the type of milk consumed. The prevalence of adequacy for vitamin B12 was highly compliant by all population groups. The major contributors to vitamin B6 were milk and dairy products being significantly higher in AMS than SRS (p ≤ 0.001). The highest contributors to folates intakes were milk and dairy products, cereals, vegetables, and fruits in both groups whereas for vitamin B12 in the SRS sample were milk and dairy products followed by meat and meats products and for adapted milks, were milk and dairy products, followed by eggs, then meat and meats products.

Conclusion

A satisfactory prevalence of adequacy for vitamins B6, and B12 amongst the Spanish children population was observed, which was not the case for folates, regardless of the dietary group evaluated. Nevertheless, a possible strategy to increase folate intake among the youngest children is to increase the consumption of milk and dairy products within a healthier dietary pattern, as these may contribute significantly to the vitamin needs of the infant population.

The Epidemiology of Deficiency of Vitamin B12 in Preschool Children in Turkey

Background: Vitamin B12 is a water-soluble vitamin with important cellular functions; it is an essential vitamin. The aim of this study is to determine the B12 levels of children in the period from the 6th month when they start taking additional foods to the age of seven (preschool children) and the risk factors affecting them. Methods: One hundred pediatric patients aged 6-72 months who were diagnosed with vitamin B12 deficiency and their parents who agreed to attend Istanbul Atlas University, Medical Faculty, "Medicine Hospital" Pediatric Clinic between September 2022 and June 2023 were prospectively included in this study. Results: B12 deficiency was significantly higher in the 6-11 (25%)-month group than in the 12-23 (5.8%)- and 24-47 (2.8%)-month groups. Homocysteine levels were highest in those with insufficient B12 levels compared to the other groups. There was no statistically significant difference in weekly dairy and meat consumption levels between age groups. B12 levels were lower in the 6-11-month group than in the other groups. Homocysteine levels were highest in those with insufficient B12 levels (<200 pg/mL (148 pmol/L)). Folic acid levels were lower in the 24-47-month and 48-72-month groups than in the 6-11-month and 12-23-month groups. Conclusions: The results obtained in this study showed that low vitamin B12 and increased homocysteine levels seem to be important risk factors in preschool children, especially from the 6th month when they start consuming additional foods. The diagnosis of B12 deficiency can be confirmed by elevated serum total homocysteine levels, which are evidence of functional cobalamin deficiency.

Status of Vitamin B12, Zinc, Copper, Selenium, Manganese, Molybdenum and Cobalt in Severe Acute Malnutrition

OBJECTIVES

To define the vitamin B12 levels and other micronutrients status in severe acute malnutrition (SAM) children.

METHODS

This was a prospective hospital based cross-sectional study.

INCLUSION CRITERIA

Children with severe acute malnutrition as per WHO criteria.

EXCLUSION CRITERIA

(i) Pernicious anemia (ii) Autoimmune gastritis (iii) SAM children on exclusive vitamin B12 supplementation. All enrolled children underwent a detailed clinical history, general physical examination with more emphasis on clinical features of vitamin B12 and other micronutrients deficiencies. Three ml of venous blood was collected to estimate vitamin B12 and other micronutrients. Primary outcome was percentage of deficiency of serum vitamin B12, zinc, copper, selenium, manganese, molybdenum and cobalt in SAM children.

RESULTS

Fifty children were included in the study. The mean age of children was 15.60±12.90 mo with male to female ratio 0.85:1. The common clinical presentation in order of frequency were upper respiratory infection (URI) symptoms 35 (70%), hepatomegaly 24 (48%), Hyperpigmentation 17 (34%), angular cheilitis 14 (28%), tremors 11 (22%), edema 07 (14%), and hypotonia 05 (10%). Anemia was found in 44 (88%) children. Prevalence of vitamin B12 deficiency was 34%. Other micronutrient deficiencies observed were cobalt 24 (100%), copper 05 (12%), zinc 04 (9.5%), and molybdenum 03 (12.5%). No statistical significance was found between clinical symptoms and levels of vitamin B12 with different age and sex.

CONCLUSIONS

Prevalence of low vitamin B12 and cobalt were more common than other micronutrients.

Comparison of Serum Selenium, Homocysteine, Zinc, and Vitamin D Levels in Febrile Children with and without Febrile Seizures: A Prospective Single-Center Study

OBJECTIVE

Febrile seizure is a complication that makes physicians and families uneasy when detected in children with a high fevers. This study aimed to compare children with febrile seizures and children without seizures in blood selenium, zinc, homocysteine, vitamin D, vitamin B12, and magnesium levels.

MATERIALS AND METHODS

The study group included sixty-one children between the ages of 1-5 who came to the pediatric emergency department with febrile seizure. The control group had 61 children with fever without seizure, who were compatible with the study group in age, sex, and elapsed time since the onset of fever. Blood samples were taken from the patients during their admission. Selenium, zinc, vitamin D, homocysteine, vitamin B12, and magnesium levels were measured, and the data of the two groups were compared. Additionally, patients in the study group had two subgroups, simple and complex febrile seizures, and their parameters were compared.

RESULTS

Selenium, zinc, vitamin D, and vitamin B12 levels were significantly lower in the study group than in the control group (p < 0.001), and there was no significant difference in homocysteine (p = 0.990) and magnesium levels (p = 0.787) between the two groups. Moreover, no significant difference was found between those with simple and complex febrile seizures in selenium, vitamin D, homocysteine, vitamin B12, and magnesium levels.

CONCLUSIONS

Elevated levels of selenium, zinc, vitamin D, and vitamin B12 in the blood of children with fevers help to prevent febrile seizures.

Newborn screening for propionic, methylmalonic acidemia and vitamin B12 deficiency. Analysis of 588,793 newborns

OBJECTIVES

We present the results of our experience in the diagnosis and follow up of the positive cases for propionic, methylmalonic acidemias and cobalamin deficiencies (PA/MMA/MMAHC) since the Expanded Newborn Screening was implemented in Madrid Region.

METHODS

Dried blood samples were collected 48 h after birth. Amino acids and acylcarnitines were quantitated by MS/MS. Newborns with alterations were referred to the clinical centers for follow-up. Biochemical and molecular genetic studies for confirmation of a disease were performed.

RESULTS

In the period 2011-2020, 588,793 children were screened, being 953 of them were referred to clinical units for abnormal result (192 for elevated C3 levels). Among them, 88 were false positive cases, 85 maternal vitamin B12 deficiencies and 19 were confirmed to suffer an IEM (8 PA, 4 MMA, 7 MMAHC). Ten out 19 cases displayed symptoms before the NBS results (6 PA, 1 MMA, 3 MMAHC). C3, C16:1OH+C17 levels and C3/C2 and C3/Met ratios were higher in newborns with PA/MMA/MMAHC. Cases diagnosed with B12 deficiency had mean B12 levels of 187.6 ± 76.9 pg/mL and their mothers 213.7 ± 95.0; 5% of the mothers were vegetarian or had poor eating while 15% were diagnosed of pernicious anemia. Newborns and their mothers received treatment with B12 with different posology, normalizing their levels and the secondary alterations disappeared.

CONCLUSIONS

Elevated C3 are a frequent cause for abnormal result in newborn screening with a high rate of false positive cases. Presymptomatic diagnosis of most of PA and some MMA/MMAHC is difficult. Vitamin B12 deficiency secondary to maternal deprivation is frequent with an heterogenous clinical and biochemical spectrum.

Hydroxocobalamin Treatment and Pediatric Migraine Disability Assessment Scale Scores

Migraine is a common neurologic disorder in children, especially in adolescents. It can affect the school performance, family, and social daily activities. The Pediatric Migraine Disability Assessment Scale (PedMIDAS) is commonly used in young patients. This study evaluated vitamin B12 deficiency in children with migraine and the effect of hydroxocobalamin treatment on PedMIDAS scores. The study group comprised patients with vitamin B12 deficiency and diagnosed migraine. The PedMIDAS questionnaire was conducted before and 3 months after hydroxocobalamin treatment. PedMIDAS scores were evaluated and compared before and after hydroxocobalamin treatment. The mean ± standard deviation of vitamin B12 level was 175.9 ± 21.3 pg/mL in children with migraine. The PedMIDAS scores were significantly lower after hydroxocobalamin treatment than before treatment (p < 0.001). These results indicated that hydroxocobalamin made a positive contribution to the mitigation of migraine symptoms in children and that treating vitamin B12 deficiency could be a useful option.

Cranial Magnetic Resonance Imaging Findings in Hypotonic Infants with Cobalamin Deficiency and Combined Methylmalonic Aciduria and Homocystinuria

Vitamin B12 begins to accumulate in infants within the first six months while mothers often remain asymptomatic and infantile vitamin B12 deficiency may not be noticed until the onset of neurological effects. In infants with Cbl deficiency, long-term exposure to elevated methylmalonic acid and homocysteine (MMA-HC) may have toxic effects on the central nervous system. The aim of this study was to evaluate cranial magnetic resonance (MRI) findings of 23 hypotonic infants that were followed up with a diagnosis of nutritional Cbl deficiency and combined MMA-HC. Of the 78 infants that presented with hypotonicity, 23 (29.4%) infants were detected with vitamin B12 deficiency. Elevated MMA-HC levels were detected in all patients (100%). Cranial MRI showed cortical atrophy in 6 (26.0%)-large sylvian fissures in 7 (30.4%)-ventricular dilatation in 5 (21.7%)-corpuscallosal thinning in 6 (26.0%)-delayed myelination in 3 (13%), and normal in 8 (34.7%) infants.Infants detected with corpus callosal thinning and cortical atrophy on MRI. Vitamin B12 deficiency is a treatable condition, it should be suspected in infants presenting with hypotonicity. Neuroradiological findings should be considered in the diagnosis of such patients. İnfantile nutritional vitamin B12 deficiency, which can be a source of persistent neurological deficits during the long term, should be treated to allow the patient to allow healthy neuro-development for infants. Maternal and fetal vitamin B12 levels should be assessed during the third trimester of pregnancy to prevent long-term exposure to infantile vitamin B12 deficiency.

Microcytic Anemia Hiding Vitamin B12 Deficiency Anemia

Vitamin B12 is an essential water-soluble vitamin that mediates multiple coenzymes needed for cell synthesis, mainly the red blood cells. Its deficiency is characterized by megaloblastic anemia and neuropsychiatric symptoms. Macrocytosis is the classical picture seen usually, but having microcytosis is unlikely. We report a case series of three cousins with vitamin B12 deficiency who presented with microcytosis.

Hearing status in vitamin B12-deficient children

AIM

The aim of this study is to investigate the effects of vitamin B12 deficiency on hearing in school-aged children by pure-tone audiometry.

METHODS

Forty-three vitamin B12-deficient children and 37 age-matched control subjects were enrolled in the study. Tympanometric evaluations and pure-tone audiometry including high frequencies were performed on the subjects. The results were compared between the two groups.

RESULTS

Both right and left ear pure-tone hearing thresholds (PTHTs) at 0.25-4 kHz, and four-frequency pure-tone average values were significantly better in the control group compared with the patient group (P < 0.05). However, PTHTs at 8-16 kHz were not different between the two groups (P > 0.05). Vitamin B12 level also did not show any significant correlation with the PTHTs at 0.25-16 kHz (P > 0.05).

CONCLUSION

This study indicates that vitamin B12 deficiency may contribute to hearing impairment at low frequencies as a possible aetiological factor in children.

Implementation of second-tier tests in newborn screening for the detection of vitamin B12 related acquired and genetic disorders: results on 258,637 newborns

BACKGROUND

Alteration of vitamin B₁₂ metabolism can be genetic or acquired, and can result in anemia, failure to thrive, developmental regression and even irreversible neurologic damage. Therefore, early diagnosis and intervention is critical. Most of the neonatal cases with acquired vitamin B₁₂ deficiency have been detected by clinical symptoms and only few of them trough NBS programs. We aim to assess the usefulness of the second-tier test: methylmalonic acid (MMA), methylcitric acid (MCA) and homocysteine (Hcys) in our newborn screening program and explore the implications on the detection of cobalamin (vitamin B₁₂) related disorders, both genetic and acquired conditions.

METHODS

A screening strategy using the usual primary markers followed by the analysis of MMA, MCA and Hcys as second tier-test in the first dried blood spot (DBS) was developed and evaluated.

RESULTS

During the period 2015-2018 a total of 258,637 newborns were screened resulting in 130 newborns with acquired vitamin B₁₂ deficiency (incidence 1:1989), 19 with genetic disorders (incidence 1:13,613) and 13 were false positive. No false negatives were notified. Concerning the second-tier test, the percentage of cases with MMA above the cut-off levels, both for genetic and acquired conditions was very similar (58% and 60%, respectively). Interestingly, the percentage of cases with increased levels of Hcys was higher in acquired conditions than in genetic disorders (87% and 47%, respectively). In contrast, MCA was high only in 5% of the acquired conditions versus in 53% of the genetic disorders, and it was always very high in all patients with propionic acidemia.

CONCLUSIONS

When screening for methylmalonic acidemia and homocystinuria, differential diagnosis with acquired vitamin B₁₂ deficiency should be done. The results of our strategy support the inclusion of this acquired condition in the NBS programs, as it is easily detectable and allows the adoption of corrective measures to avoid the consequences of its deficiency.

Evaluation of macular, retinal nerve fiber layer and choroidal thickness by optical coherence tomography in children and adolescents with vitamin B12 deficiency

PURPOSE

To investigate macular, Retinal Nerve Fiber Layer (RNFL) and choroidal thickness in children and adolescents with vitamin B₁₂ deficiency and no neurological examination finding.

METHODS

The study group includes of thirty-three children aged 8-17 years who were brought to the Pediatric outpatient clinic with the symptoms of fatigue and forgetfulness and whose Vitamin B₁₂ levels were detected < 200 pg/ml. The control group was the 30 children and adolescents applied to the same policlinic with various symptoms and whose Vitamin B₁₂ levels were found normal. Children and adolescents with chronic systemic/ocular disease history and myopia or hyperopia more than 4 diopters were not included in both groups. Spectral Domain-Optical Coherence Tomography (SD-OCT) was used for measurements.

RESULTS

Mean Macular thickness value was 261.2 ± 17.6 in the Vitamin B₁₂ deficiency group and 267.7 ± 17.4 in the control group. Mean value of Retinal Nerve Fiber Layer (RNFL) thickness was 103.5 ± 7.5 in the Vitamin B₁₂ deficiency group and 104.3 ± 8.9 in the control group. The mean values of Choroidal thickness were 360.1 ± 59.8 and 316.9 ± 95.4 in Vitamin B₁₂ deficiency and control groups, respectively. There was a statistically significant increase in choroidal thickness in Vitamin B₁₂ deficiency group compared to controls.

CONCLUSION

Statistically significant increase in the Choroidal thicknesses of children and adolescents with Vitamin B₁₂ deficiency is important in terms of shedding light on studies that will contribute to a better understanding of the relationship between vitamin B₁₂ and inflammation.

CLINICAL TRIAL REGISTRATION

This study is an observational study.

Assessment of Vitamin B12 Deficiency and Risk Factors in Healthy Infants

OBJECTIVE

To study vitamin B₁₂ deficiency in apparently healthy infants and their mothers and assess the risk factors.

METHODS

A hospital-based, cross-sectional, observational study was conducted from July 2016 through December 2017. Consecutive healthy and normally developing infants were enrolled. Red blood cell folate, plasma vitamin B₁₂, homocysteine and methylmalonic acid levels of mothers and infants were assessed.

RESULTS

Seventy-four healthy infants were enrolled. Male-to-female ratio was 1.5:1. Anemia in 66.2% (n = 49), low plasma B₁₂ in 17.6% (n = 13), hyperhomocysteinemia in 48.6% (n = 36), plasma methylmalonic acid in 100% (n = 74) and 'confirmed' B₁₂ deficiency in 38% (n = 28) infants were noted. The proportion of hyperhomocysteinemia increased to 75.7% (n = 56) infants using a lower cut-off of >10 μmol/L. In mothers, low B₁₂ in 19%, hyperhomocysteinemia in 57% and elevated plasma methylmalonic acid in 100% were noted. Median plasma B₁₂ level was 314 pg/ml (IQR 221-421), median plasma homocysteine 15.4 μmol/L (IQR 11.3-21.7) and median plasma methylmalonic acid was 8.28 μmol/L (IQR 4.4-13.1) in mothers. Folate deficiency was noted in 9.4% infants and 12% of mothers. Overall, 63.5% mothers were vegetarian and, 64% of the mothers of infants with confirmed vitamin B12 deficiency were pure vegetarians. Odds of developing vitamin B₁₂ deficiency increased by more than 5 times in those whose mothers' serum vitamin B₁₂ levels were low as compared to normal maternal vitamin B₁₂ levels (OR 5.42; 95% CI: 1.96-16.6; p 0.002).

CONCLUSIONS

There is a high prevalence of vitamin B₁₂ deficiency in infants and their mothers. There is urgent need to supplement our population with vitamin B₁₂.

Malnutrition and Medical Neglect

Anomalies found during the assessment of nutrition in children are common in pediatric practice, yet few articles address the intersection between malnutrition and medical neglect. The diagnosis of medical neglect requires several components including a) harm, or risk of harm due to lack of recommended health care, b) recommended care provides benefit significantly greater than potential risk, c) caregiver understands the medical recommendations; and d) has access to the recommended care, but fails to utilize it. Through the application of this definition to cases of malnutrition, considerations for diagnosing medical neglect when presented with malnutrition are reviewed. Cases include children with special healthcare needs, children exposed to selective diets, previously well children with severe malnutrition, and treatment-resistant failure to thrive. Obesity is a state of malnutrition, which may also involve neglect; in this instance, the "neglect" involves failure to supervise nutritional intake necessary for optimal functioning. Because many cases involve interactions with medical providers, the subsequent failure to follow medical advice regarding obesity management may also be considered medical neglect. This article reviews the relationship between medical neglect, nutritional deprivation, and over-nutrition to explore when a diagnosis of medical neglect may be applicable.

Utilization of B12 for the treatment of chronic migraine

Chronic migraine is a particular classification of a headache that is typically unilateral and pulsatile and lasts for at least 3 months. Owing to its high prevalence and detrimental impact on personal, social, and economic aspects of patient lives, much desire has gone into fully understanding the pathogenesis of migraine, and to search for therapeutic agents. In addition to current therapeutics such as triptans, ergotamine, and monoclonal antibodies targeting calcitonin gene-related peptide receptors, vitamin B12 has been investigated for its possible use as a prophylactic agent for migraines. Specifically, the observed effects of vitamin B12 on nitric oxide and homocysteine prompt further investigation of its underlying mechanisms in migraine pathophysiology. In this comprehensive review, we provide a brief overview of migraines and current therapies while focusing on the promising role of vitamin B12 as a possible treatment option for chronic migraine management.

Diagnostic Challenges Using a 2-Tier Strategy for Methylmalonic Acidurias: Data from 1.2 Million Dried Blood Spots

BACKGROUND

The detection of methylmalonic acid (MMA) by second-tier analysis has been shown to reduce the number of false positives in newborn screening (NBS) for genetically determined methylmalonic acidurias (MMAuria). In addition to genetic conditions, MMA is an indicator of vitamin B12 status, thus applicable to detect maternal vitamin B12 deficiency in the newborns screened.

METHODS

Biochemical and clinical follow-up data of a 7.5-year pilot study with 1.2 million newborns screened were reviewed.

RESULTS

Among 1,195,850 NBS samples, 3,595 (0.3%) fulfilled criteria for second-tier analysis of MMA. In 37 (0.003%; 1/32,000) samples, elevated concentrations of MMA were detected, resulting in diagnostic workup at a metabolic center in 21 newborns. In 6 infants (1/199,000), genetic conditions were established, 1 infant with cobalamin C deficiency (CblC) showed only a moderate elevation of MMA. The remaining 15 newborns (1/79,000) displayed significantly lower concentrations of MMA and were evaluated for maternal vitamin B12 deficiency. In 9 mothers, vitamin B12 deficiency was verified, and 6 showed no indication for vitamin B12 deficiency. Treatment with vitamin B12 normalized biochemical parameters in all 15 infants.

CONCLUSIONS

Applying a 2-tier strategy measuring MMA in NBS identified genetic conditions of MMAuria. It was possible to separate severe, early-onset phenotypes from maternal vitamin B12 deficiency. However, the detection of CblC deficiency with mildly elevated MMA interferes with impaired vitamin B12 status of unknown relevance and thus burdens possibly healthy newborns. Regarding maternal vitamin B12 deficiency, testing and supplementing mothers-to-be is preferable. This might decrease straining follow-up of newborns and improve quality and overall perception of NBS.

Cerebral atrophy in 21 hypotonic infants with severe vitamin B12 deficiency

AIM

Nutritional B12 deficiency is a treatable cause of neurodevelopmental delay in infants. We report 21 infants with developmental regression and brain atrophy as revealed using cranial magnetic resonance imaging (MRI), secondary to severe vitamin B12 deficiency.

METHODS

Twenty-one infants aged 4-24 months with B12 deficiencies who were admitted to our clinic between May 2013 and May 2018 were included in the study. MRI, bone marrow aspiration and the Denver-II Developmental Screening Test were performed in all infants.

RESULTS

The mean age of the infants was 12.3 months, and the mean B12 level was 70.15 ± 32.15 ng/L. Hypotonia and neurodevelopmental retardation, and anaemia were present in all patients. Their bone marrow examinations were compatible with megaloblastic anaemia. Twelve patients had microcephaly, seven had tremor and one patient died of severe sepsis. Almost all patients were fed with breast milk and their mothers were also malnourished. Nine (42.9%) of the patients were Turkish and 12 (57.1%) were Syrian. All patients had abnormal Denver-II Developmental Screening Test scores. Most patients had severe cortical atrophy, cerebral effusion, thinning of the corpus callosum and delayed myelinisation in cranial MRI. Treatment with B12 resulted in dramatic improvement in general activity and appetite within 72 h. Tremors resolved in all cases.

CONCLUSION

Neurological findings and developmental delay related to nutritional B12 deficiency can be prevented without sequelae if diagnosed early. Screening and treating of mothers for this deficiency will contribute to the health of both the mother and their feeding infant.

Weakness, Anemia, and Neutropenia in a 9-Year-Old Girl With Influenza

A previously healthy 9-year-old immigrant girl from Mexico was evaluated in the emergency department (ED) with one week of fatigue, fevers, rhinorrhea, and cough. She initially presented to her primary pediatrician, where a complete blood count revealed neutropenia, prompting referral to the ED. In the ED, she was found to be influenza A-positive. Because of dehydration, she received intravenous fluids and was admitted to the pediatric hospital medicine service. After 2 days, influenza symptoms improved, and oral intake increased. However, she was noted to have decreased bilateral lower-extremity strength, absent Achilles reflexes, decreased lower-extremity sensation and proprioception, a positive result on the Romberg sign, and abnormal heel-to-shin testing results. These findings prompted an urgent neurology consultation. After extensive imaging, laboratory evaluation, and further consultations, a diagnosis was established.

Metabolomics to Improve the Diagnostic Efficiency of Inborn Errors of Metabolism

Early diagnosis of inborn errors of metabolism (IEM)—a large group of congenital disorders—is critical, given that many respond well to targeted therapy. Newborn screening programs successfully capture a proportion of patients enabling early recognition and prompt initiation of therapy. For others, the heterogeneity in clinical presentation often confuses diagnosis with more common conditions. In the absence of family history and following clinical suspicion, the laboratory diagnosis typically begins with broad screening tests to circumscribe specialised metabolite and/or enzyme assays to identify the specific IEM. Confirmation of the biochemical diagnosis is usually achieved by identifying pathogenic genetic variants that will also enable cascade testing for family members. Unsurprisingly, this diagnostic trajectory is too often a protracted and lengthy process resulting in delays in diagnosis and, importantly, therapeutic intervention for these rare conditions is also postponed. Implementation of mass spectrometry technologies coupled with the expanding field of metabolomics is changing the landscape of diagnosing IEM as numerous metabolites, as well as enzymes, can now be measured collectively on a single mass spectrometry-based platform. As the biochemical consequences of impaired metabolism continue to be elucidated, the measurement of secondary metabolites common across groups of IEM will facilitate algorithms to further increase the efficiency of diagnosis.

Impact of Beef and Beef Product Intake on Cognition in Children and Young Adults: A Systematic Review

(1) Background: Undernutrition and micronutrient deficiency have been consistently linked to cognitive impairment among children and young adults. As a primary source of dietary animal protein, beef consumption holds the potential to improve diet quality and positively influence cognitive function. This study systematically reviewed evidence linking beef intake to cognition among children and young adults. (2) Methods: A literature search was conducted in seven electronic bibliographic databases for studies assessing the impact of beef consumption on cognition. (3) Results: We identified eight studies reporting results from five unique interventions. Two interventions were conducted in Kenya, two in the U.S. and one in four countries including Guatemala, Pakistan, Democratic Republic of the Congo and Zambia. Only one intervention employed a non-feeding control arm and found beef consumption to improve cognitive abilities compared to the control. However, the other interventions comparing beef consumption to other food types found no consistent result. (4) Conclusions: Evidence pertaining to the impact of beef consumption on cognition remains limited due to the small and heterogeneous set of studies. Future research should adopt a population representative sample and longer follow-up period, employ a non-feeding control arm and comprehensively measure nutrient intakes among study participants.

A Rare Cause of Pancytopenia in an Exclusively Breastfed Infant

Vitamin B12 (B12) deficiency in infancy can present with nonspecific symptoms. We report a 5-month old exclusively breastfed full-term infant with emesis, lethargy, progressive pancytopenia, hemolysis, hypofibrinogenemia, elevated lactate dehydrogenase and a hypercellular bone marrow with dyserythropoiesis. The B12 level in the serum was undetectable. The infant's lethargy resolved within 48 hours of intramuscular B12 injection, followed by rapid improvement of pancytopenia. The asymptomatic mother had a normal hemoglobin and mean corpuscular volume, but undetectable B12 level and positive antibodies to intrinsic factor, consistent with pernicious anemia masked by folate supplementation in the mother but causing symptoms in her infant.

Neurological symptoms of vitamin B12 deficiency: analysis of pediatric patients

Vitamin B12 is one of the essential vitamins that affect various systems in the body, including the central nervous system. Vitamin B12 plays an important part in the metabolism of the nervous system, although its exact role under pathological conditions is not fully understood. The purpose of this study was to emphasize the importance of early diagnosis of vitamin B12 deficiency in the light of the characteristics of the patients enrolled. This retrospective, clinical study included 38 children with neurological symptoms of vitamin B12 deficiency. Records of 38 patients referred to a single center of the university hospital outpatient child neurology clinic due to neurological symptoms of vitamin B12 deficiency between February 2012 and December 2013 were evaluated retrospectively. Patients aged 0-18 years with symptoms including syncope, dizziness, convulsion, hypotonia, developmental retardation, tremor, ataxia, tingling sensations and paresthesia, blurring of vision, fatigue and concentration difficulty caused by vitamin B12 deficiency were included in the study. Patient neurological findings included syncope (n=6), dizziness (n=4), hypotonia (n=9), inability to sit or walk without support, or gait ataxia (n=2), convulsion (n=4), hand tremor (n=1), tingling sensations and paresthesia (n=3), vision blurring (n=1), fatigue and concentration difficulty (n=8). All patients with neurological symptoms of vitamin B12 deficiency recovered within one month after vitamin B12 supplementation. In conclusion, clinical characteristics of vitamin B12 deficiency are broad and nonspecific and may not be associated with anemia and increased mean corpuscular volume. Since different clinical characteristics can be seen without anemia, awareness and cautious approach are essential in order to avoid severe clinical disease, especially in children from underdeveloped countries.

Dermatologic findings of vitamin B12 deficiency in infants

BACKGROUND/OBJECTIVES

Vitamin B₁₂ deficiency in infants is uncommonly reported from developed countries and generally lacks dermatologic manifestations. On the contrary, infantile vitamin B₁₂ deficiency is common in India and cutaneous manifestations are a constant feature, although often overshadowed by neurologic and hematological manifestations. The aim of this study was to describe the skin changes of vitamin B₁₂ deficiency in infants.

MATERIALS AND METHODS

A retrospective chart review of vitamin B₁₂ deficient infants for clinical and laboratory parameters was performed and data analyzed.

RESULTS

Forty-three infants, 30 boys and 13 girls, aged 4 to 27 months, with vitamin B₁₂ deficiency were identified. Skin hyperpigmentation was present in 41 infants; it was localized to the dorsa of hands and feet in 26. Fifteen infants had generalized hyperpigmentation; 10 had a reticulate pattern, and 5 had a homogeneous pattern. Brown and sparse scalp hair were present in all. Glossitis was seen in 5 infants and cheilitis in 3. Of the 32 infants who underwent laboratory investigations, 28 had anemia and 21 macrocytosis. Serum vitamin B₁₂ was measured in 30 infants; it was low in 19. Of the 11 with normal serum vitamin B₁₂ , 9 had received vitamin B₁₂ before referral but had macrocytosis and low maternal serum vitamin B₁₂ . The infants were treated with vitamin B₁₂ . Skin pigmentation and mucosal changes resolved completely by 3-4 weeks, but hair changes were slower to reverse.

CONCLUSION

Cutaneous findings are a common feature of vitamin B₁₂ deficiency in Indian infants and resolve with treatment.

Psychomotor regression due to vitamin B12 deficiency

A vitamin B12 deficiency in infants is rare, but may sometimes be seen in breastfed babies of strict vegetarian mothers. Vitamin B12, also known as cobalamin, is only found in meat and other animal products. Most babies have a sufficient supply as long as the mother was not deficient herself. Symptoms and signs of vitamin B12 deficiency appear between the ages of 2 to 12 months and include vomiting, lethargy, failure to thrive, hypotonia, and arrest or regression of developmental skills. Urinary concentrations of methylmalonic acid and homocystine are characteristically elevated in vitamin B12 deficiency. Early treatment for a vitamin B12 deficiency in an infant involves immediate administration of vitamin B12 to the baby and the breastfeeding mother. The infant and mother will each receive an injection of vitamin B12 containing 1,000 mcg or more of the vitamin, and the mother will continue to receive injections every month to raise her own stores. After the initial injection, the baby will often receive future vitamin B12 through food sources. We present a case of vitamin B12 deficiency in a 9-month-old girl presented with psychomotor regression, hypotonia and lethargy. The child was exclusively breast-fed from birth by a mother who was on strict vegetarian diet and belong to a low socio-economic status. Laboratory data revealed bicytopenia with macrocytic anemia and methylmalonic acid in the urine, consistent with vitamin B12 deficient anemia. The Brain CT revealed a cerebral atrophy and delayed myelination. Vitamin B12 supply was effective on anaemia and psychomotor delay. This case figures out the importance of an early diagnosis in front of psychomoteur regression and hypotonia, given the risk of incomplete neurologic recovery due to vitamin B12 deficiency mainly in the setting of maternal nutritional deficiency.

High incidence of low vitamin B12 levels in Estonian newborns

Vitamin B12 deficiency seems to be more common worldwide than previously thought. However, only a few reports based on data from newborn screening (NBS) programs have drawn attention to that subject. In Estonia, over the past three years, we have diagnosed 14 newborns with congenital acquired vitamin B12 deficiency. Therefore, the incidence of that condition is 33.8/100,000 live births, which is considerably more than previously believed. None of the newborns had any clinical symptoms associated with vitamin B12 deficiency before the treatment, and all biochemical markers normalized after treatment, which strongly supports the presence of treatable congenital deficiency of vitamin B12. During the screening period, we began using actively ratios of some metabolites like propionylcarnitine (C3) to acetylcarnitine (C2) and C3 to palmitoylcarnitine (C16) to improve the identification of newborns with acquired vitamin B12 deficiency. In the light of the results obtained, we will continue to screen the congenital acquired vitamin B12 deficiency among our NBS program. Every child with aberrant C3, C3/C2 and C3/C16 will be thoroughly examined to exclude acquired vitamin B12 deficiency, which can easily be corrected in most cases.

Cobalamin and Folate Status among Breastfed Infants in Bhaktapur, Nepal

Cobalamin and folate are crucial micronutrients during infancy and they are required for growth and cognitive development. Due to the monotonous and predominantly vegetarian-based complementary feeding and poor maternal micronutrient status, infants from low- and middle-income countries are susceptible to cobalamin deficiency. However, data on plasma cobalamin and folate and the functional markers methylmalonic acid and total homocysteine from breastfed infants in Nepal are still needed. We collected plasma samples from 316 6–11-month-old breastfed infants with a length-for-age of less than minus one z-score and analyzed blood for plasma folate, cobalamin, methylmalonic acid and total homocysteine concentrations. Cobalamin deficiency (plasma cobalamin <148 pmol/L) was found among 11%, whereas 24% of the infants had plasma cobalamin concentrations between 148–221 pmol/L. Elevated total homocysteine (>10 µmol/L) and methylmalonic acid (>0.28 µmol/L) indicating functional cobalamin deficiency were found among 53% and 75% of the infants, respectively. Based on a combined indicator of cobalamin status, 58% were found to have low cobalamin status. However, folate deficiency (<10 nmol/L) was not found as the lowest value of plasma folate was 20.7 nmol/L. It is important to examine the extent to which poor cobalamin status during infancy has immediate or long-term consequences.

Micronutrient Status and Nutritional Intake in 0- to 2-Year-old Children Consuming a Cows' Milk Exclusion Diet

OBJECTIVES

To study micronutrient status and nutritional intake from complementary feeding in children on a cows' milk exclusion (CME) diet.

METHODS

Fifty-seven children with cows' milk allergy, younger than 2 years, were included in a cross-sectional study. Blood was analyzed for micronutrient status. Complementary feeding was defined as all solids and liquids except of breast milk, and assessed by 3-day food diary. The results were analyzed according to 3 feeding patterns: mainly breast-fed (mBF), partially breast-fed, and no breast milk group (nBM).

RESULTS

The children had a median age of 9 months and micronutrient status was within normal range for total homocysteine (p-tHcy), s-B12, s-folate, b-Hb, s-ferritin, s-zinc, and s-25(OH)D. There were no significant differences between feedings groups, except for B12-biomarkers. The mBF had higher p-tHcy (P < 0.000) and lower s-B12 (P = 0.002) compared nBM. Vitamin B12 deficiency (p-tHcy >6.5 μmol/L combined with s-B12 <250 pmol/L) was found in 12% of participants, most frequently among the mBF (36%) and none in nBM group (P = 0.009). Vitamin B12 intake from complementary feeding was negatively correlated with p-tHcy (r = -0.479, P = 0.001) and positively with s-B12 (r = 0.410, P = 0.003). Iron deficiency anemia was found in 5%. Iron intake correlated positively with b-Hb (r = 0.324, P = 0.02). Zinc deficiency was found in 7% and low 25(OH)D in 9%. Vitamin D intake was positively correlated with the use of supplements (r = 0.456, P = 0.001).

CONCLUSION

The risk of B12 deficiency was high in mBF infants on CME diet, and complementary feeding was associated with better B12 status. Iron, zinc, and vitamin D deficiencies were present in all feeding groups. Complementary feeding should be introduced at 4 to 6 months of age. Vitamin D supplement is recommended to ensure adequate intake.

Vitamin Excess and Deficiency

The published literature supports the high prevalence of supplement use in children and adolescents in the United States. Pediatricians today are faced with questions from parents and patients about the benefits, safety, efficacy, and correct dose of vitamins and minerals. In this article, we review 7 vitamins with the most clinical relevance as judged by abundance in food, risks and symptoms of deficiency, and potential for toxicity. Specifically, we focus on possible clinical scenarios that can be indicative of nutritional deficiency. We synthesize and summarize guidelines from nutrition experts, various medical societies, the World Health Organization, and the American Academy of Pediatrics.

The Efficacy of Oral Vitamin B12 Replacement for Nutritional Vitamin B12 Deficiency

Standard treatment of vitamin B12 deficiency has not been well established in childhood, the ideal amount of supplemental vitamin B12 is not clear. Vitamin B12 deficiency is classically treated with intramuscular injections. In this study, we aimed to investigate the efficacy of oral therapy in children with vitamin B12 deficiency. Patients with serum cobalamin concentrations <300 pg/mL aged between 6 months to 18 years were included in this prospective study. Children were treated orally either with a combination of multivitamin tablet daily or vitamin B12 ampules. Serum specimens were obtained at the end of first and third months of treatment for vitamin B12 levels. A total of 79 patients were included in the study. The mean pretreatment vitamin B12 level increased from 182±47.6 pg/mL to 482±318 pg/mL after 1 month of treatment in the whole cohort. Comparison of the pretreatment vitamin B12 levels with first and third month posttreatment values showed significant difference (P-value, 0.001 and 0.028, respectively). In this study, oral cyanocobalamin was found effective for the treatment of vitamin B12 deficiency in children.

Is vegetarianism healthy for children?

According to the Academy of Nutrition and Dietetics' influential position statement on vegetarianism, meat and seafood can be replaced with milk, soy/legumes, and eggs without any negative effects in children. The United States Department of Agriculture endorses a similar view. The present paper argues that the Academy of Nutrition and Dietetics ignores or gives short shrift to direct and indirect evidence that vegetarianism may be associated with serious risks for brain and body development in fetuses and children. Regular supplementation with iron, zinc, and B12 will not mitigate all of these risks. Consequently, we cannot say decisively that vegetarianism or veganism is safe for children.

Maternofetal transport of vitamin B12: role of TCblR/CD320 and megalin

Vitamin B₁₂ deficiency causes megaloblastic anemia and neurologic disorder in humans. Gene defects of transcobalamin (TC) and the transcobalamin receptor (TCblR), needed for cellular uptake of the TC-bound B₁₂, do not confer embryonic lethality. TC deficiency can produce the hematologic and neurologic complications after birth, whereas TCblR/CD320 gene defects appear to produce mild metabolic changes. Alternate maternofetal transport mechanisms appear to provide adequate B₁₂ to the fetus. To understand this mechanism, we evaluated the role of TC, TCblR/CD320, and megalin in maternofetal transport of B₁₂ in a TCblR/CD320-knockout (KO) mouse. Our results showed high expression of TCblR/CD320 in the labyrinth of the placenta, embryonic brain, and spinal column in wild-type (WT) mice. Megalin expression was about the same in both WT and KO mouse visceral yolk sac, brain, and spinal column. Megalin mRNA was down-regulated in the KO embryonic spinal cord (SC) and kidneys. Megalin expression remained unaltered in adult WT and KO mouse brain, SC, and kidneys. Injected dsRed-TC-B₁₂ and TC-⁵⁷CoB₁₂ accumulated in the visceral yolk sac of KO mice where megalin is expressed and provides an alternate mechanism for the maternofetal transport of Cbl during fetal development.-Arora, K., Sequeira, J. M., Quadros, E. V. Maternofetal transport of vitamin B₁₂: role of TCblR/CD320 and megalin.

Simultaneous determination of eight B-vitamins in rat intestinal perfusate to identify effects of osmotic pressures on absorptions

A rapid and accurate HPLC-DAD method was developed and validated to simultaneously determine eight B-vitamins (VBs, namely thiamine, riboflavin, niacinamide, calcium pantothenic, pyridoxine, biotin, folic acid and cyanocobalamin) and phenolsulfonphthalein in rat intestinal perfusate. Chromatographic separation was achieved using an Inertsil ODS-3 column (250 × 4.6 mm i.d., 5 μm) at a temperature of 40°C. Gradient elution mode was applied at the flow rate of 1.0 mL/min with the mobile phase of acetonitrile-30 mm K₂ HPO₄ (pH 5.80). The method was successfully applied to identify the effects of osmotic pressures on the absorption of the VBs. The absorption profiles of single and mixed VBs were also compared. Histological section technology was applied to observe the microstructure of small bowel mucosa after perfusion. The results indicated that each compound possessed a better absorption profile under isotonic conditions than under hypotonic or hypertonic conditions for single or mixed solutions. Compared with single VBs, better absorptions in mixed VBs were observed. Pathological tissue slice test suggested that hypotonic and hypertonic solutions changed or damaged the microstructure of mucosa to varying degrees. Taken together, the investigations indicated that multi-VBs administered orally under isotonic condition could generate fast and complete absorption profiles for VBs.

High Prevalence of Vitamin B12 Deficiency and No Folate Deficiency in Young Children in Nepal

Many children in low- and middle-income countries may have inadequate intake of vitamin B12 and folate; data confirming these inadequacies are limited. We used biochemical, demographic, behavioral and anthropometric data to describe the folate and vitamin B12 concentrations among six- to 23-month-old Nepalese children. Vitamin B12 (serum B12 < 150 pmol/L) and folate deficiencies (red blood cell (RBC) folate < 226.5 nmol/L) were assessed. We used logistic regression to identify predictors of vitamin B12 deficiency. The vitamin B12 geometric mean was 186 pmol/L; 30.2% of children were deficient. The mean RBC folate concentration was 13,612 nmol/L; there was no deficiency. Factors associated with vitamin B12 deficiency included: (a) age six to 11 months (adjusted odds ratio (aOR) 1.51; 95% confidence interval (CI): 1.18, 1.92) or 12-17 months (aOR 1.38; 95% CI: 1.10, 1.72) compared to 18-23 months; (b) being stunted (aOR 1.24; 95% CI: 1.03, 1.50) compared to not being stunted; (c) and not eating animal-source foods (aOR 1.85; 95% CI: 1.42, 2.41) compared to eating animal-source foods the previous day. There was a high prevalence of vitamin B12 deficiency, but no folate deficiency. Improving early feeding practices, including the consumption of rich sources of vitamin B12, such as animal-source foods and fortified foods, may help decrease deficiency.

B12 deficiency is common in infants and is accompanied by serious neurological symptoms

AIM

Adverse neurological symptoms have been linked to vitamin B12 deficiency in infants. This explorative study described the clinical presentation associated with vitamin B12 deficiency in this age group.

METHODS

The study comprised infants who were born between 2004 and 2012 and were tested for vitamin B12 levels after they were admitted to a hospital with neurological symptoms at less than one year of age. Vitamin B12 deficiency was defined as low cobalamin in serum and/or increased homocysteine and/or increased methylmalonate. It was diagnosed according to the applicable International Classification of Diseases, 10th revision, and recorded as vitamin B12 deficiency in the medical records. All information was retrieved from medical records and compared to symptomatic infants with normal levels.

RESULTS

Of the 121 infants tested, 35 had vitamin B12 deficiency and 86 had normal levels. Vitamin B12 deficiency was diagnosed at an average age of 1.7 months and was more common among boys. Seizures and apparent life-threatening events were the most common symptoms among infants with B12 deficiency compared to infants with normal levels.

CONCLUSION

Vitamin B12 deficiency was more common in infants than we expected and presented with severe symptoms, such as seizures and apparent life-threatening events.

Vitamin B12 Deficiency Presenting with Neurological Dysfunction in an Adolescent

BACKGROUND

Vitamin B12 deficiency is classically encountered in the adult Caucasian population and manifests as a subacute combined degeneration in the presence or absence of macrocytic anemia. However, B12 deficiency is extremely rare in children in developed countries, and pernicious anemia is even rarer etiology of this deficiency. The clinical presentation of B12 deficiency in children is not as easily recognizable or well-characterized and may result in missed or delayed diagnosis.

PATIENT DESCRIPTION

We describe a previously healthy adolescent girl who presented with emotional lability, mental status changes, hyperreflexia, and ataxia. She was found to have megaloblastic anemia and subacute combined degeneration secondary to B12 deficiency caused by pernicious anemia.

CONCLUSION

Though B12 deficiency is uncommon in pediatrics, it is important to maintain a high index of suspicion because early recognition and treatment of B12 deficiency are key to preventing long-term neurological sequelae.

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.

Vitamin B12 Deficiency in Infancy: The Case for Screening

The classic principles put forth by Wilson and Jungner are often applied to determine the suitability of a condition for universal newborn screening. The three cases described here portray the harmful effects of vitamin B12 deficiency in infancy. The challenges and opportunities of early recognition and treatment are highlighted. Screening newborns would allow early detection and prevention of severe neurological damage in vitamin B12 -deficient infants and enable diagnosis of unrecognized maternal pernicious anemia in asymptomatic mothers. However, lack of standardized methodology and screening cutoffs present challenges to the use of current tandem mass spectrometry technologies for screening.

Advances in clinical determinants and neurological manifestations of B vitamin deficiency in adults

B vitamin deficiency is a leading cause of neurological impairment and disability throughout the world. Multiple B vitamin deficiencies often coexist, and thus an understanding of the complex relationships between the different biochemical pathways regulated in the brain by these vitamins may facilitate prompter diagnosis and improved treatment. Particular populations at risk for multiple B vitamin deficiencies include the elderly, people with alcoholism, patients with heart failure, patients with recent obesity surgery, and vegetarians/vegans. Recently, new clinical settings that predispose individuals to B vitamin deficiency have been highlighted. Moreover, other data indicate a possible pathogenetic role of subclinical chronic B vitamin deficiency in neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. In light of these findings, this review examines the clinical manifestations of B vitamin deficiency and the effect of B vitamin deficiency on the adult nervous system. The interrelationships of multiple B vitamin deficiencies are emphasized, along with the clinical phenotypes related to B vitamin deficiencies. Recent advances in the clinical determinants and diagnostic clues of B vitamin deficiency, as well as the suggested therapies for B vitamin disorders, are described.

West syndrome due to vitamin B12 deficiency

Vitamin B12 is one of the essential vitamins affecting various systems of the body. Vitamin B12 deficiency in infants often produces haematological and neurological deficits including macrocyticanaemia, neurodevelopmental delay or regression, irritability, weakness, hypotonia, ataxia, apathy, tremor andseizures. In this article, we report the case of a six-month-old male patient diagnosed with West syndrome associated with vitamin B12 deficiency. Although the patient had no evidence of macrocytic anemia in complete blood count, we measured the level of vitamin B12 because the patient had hypotonicity and found it to be low. No other problem was found in the other investigations directed to the etiology of West syndrome. He was being exclusively breast-fed and vitamin B12 deficiency was related with nutritional inadequacy of his mother. Vitamin B12 deficiency should be considered in the differential diagnosis of patients presenting with different neurological findings. In addition, vitamin B12 deficiency should be considered as a rare cause in West syndrome which has a heterogeneous etiology.