Solid food refusal as the presenting sign of vitamin B12 deficiency in a breastfed infant

Biochemical, Nutritional, and Clinical Parameters of Vitamin B12 Deficiency in Infants: A Systematic Review and Analysis of 292 Cases Published between 1962 and 2022

Pooled data from published reports on infants with clinically diagnosed vitamin B12 (B12) deficiency were analyzed with the purpose of describing the presentation, diagnostic approaches, and risk factors for the condition to inform prevention strategies. An electronic (PubMed database) and manual literature search following the PRISMA approach was conducted (preregistration with the Open Science Framework, accessed on 15 February 2023). Data were described and analyzed using correlation analyses, Chi-square tests, ANOVAs, and regression analyses, and 102 publications (292 cases) were analyzed. The mean age at first symptoms (anemia, various neurological symptoms) was four months; the mean time to diagnosis was 2.6 months. Maternal B12 at diagnosis, exclusive breastfeeding, and a maternal diet low in B12 predicted infant B12, methylmalonic acid, and total homocysteine. Infant B12 deficiency is still not easily diagnosed. Methylmalonic acid and total homocysteine are useful diagnostic parameters in addition to B12 levels. Since maternal B12 status predicts infant B12 status, it would probably be advantageous to target women in early pregnancy or even preconceptionally to prevent infant B12 deficiency, rather than to rely on newborn screening that often does not reliably identify high-risk children.

Vomiting as a Presenting Symptom of Infantile Vitamin B12 Deficiency

An 8-month-old, exclusively breastfed girl presented with a five-month history of vomiting with subsequent failure to thrive and lethargy. Family history was notable for the maternal history of gastroschisis. Mother had no dietary restrictions and had successfully breastfed multiple children for >12 months without issue. Initial evaluation was notable for macrocytic anemia. Subsequent serum B₁₂ levels were undetectable. Upon further questioning, the mother had significant bowel resection as an infant due to complications of gastroschisis. Maternal serum B₁₂ levels were also undetectable. The infant’s symptoms resolved with supplementation.

Vitamine B12 deficiency in children: a diagnostic challenge

Cobalamin or vitamin B12 (vitB12) is involved in DNA synthesis, haematopoiesis and myelinisation. Consequently, vitB12 deficiency causes various symptoms, such as megaloblastic anaemia, neurologic signs or pancytopenia. Despite possible severe symptoms, vitB12 deficiency can present asymptomatically. We report six paediatric patients with different aetiologies of vitB12 deficiency ranging from a subtle to a more overt presentation. VitB12 deficiency is a diagnostic challenge due to the lack of consensus on normal values of vitB12 and its co-markers (folate, holotranscobalamin, methylmalonic acid, homocysteine) and the lack in specificity and sensitivity of the serum vitB12 analysis. All cases were treated with parenteral vitB12. Last decades, evidence supporting high dose oral treatment being as effective as the intramuscular (IM) therapy, also in children, is growing.

Gastrointestinal Conditions in Children With Severe Feeding Difficulties

Feeding aversion in children may progress to severe feeding difficulties. While oral-motor and sensory issues are usually the leading causes, organic etiologies should be considered. This study aimed to assess the prevalence of gastrointestinal conditions in children with severe feeding difficulties. We conducted a retrospective study of 93 children requiring an intensive feeding program. The medical records, radiologic and diagnostic tests, use of gastric tube feedings, preexisting medical conditions, and medications were reviewed. Fifty-two percent (52%) had esophagitis, 26.2% gastritis, and 40.7% lactase deficiency in upper endoscopy. In those who underwent an upper endoscopy, 26% of patients that were also tested for small intestinal bacterial overgrowth were found to be positive. Allergy testing was abnormal in 56.6% of those tested, while 27.5% and 75% had abnormal gastric emptying times and pH impedance results, respectively. Constipation was present in 76.3%. Thirteen of 32 were weaned off tube feedings. We conclude that gastrointestinal conditions are common in children with feeding disorders and should be investigated prior to feeding therapy.

Neurology of Nutritional Vitamin B12 Deficiency in Infants: Case Series From India and Literature Review

We studied 27 infants aged 6 to 27 months with vitamin B12 deficiency also known as "infantile tremor syndrome" in India. All were exclusively breast-fed by vegetarian mothers. Developmental delay or regression, pallor, skin hyperpigmentation, and sparse brown hair were present in all. Majority were hypotonic and involuntary movements were encountered in 18. Anemia and macrocytosis was found in 83% and 71% infants, respectively. Low serum vitamin B12 was present in 12 of 21 infants. Seven of the 9 infants with normal serum vitamin B12 had received vitamin B12 before referral. Twelve mothers had low serum vitamin B12. Cerebral atrophy was present in all the 9 infants who underwent neuroimaging. Treatment with vitamin B12 resulted in dramatic improvement in general activity and appetite within 48 to 72 hours followed by return of lost milestones. Tremors resolved in all by 3 to 4 weeks. Nutritional vitamin B12 deficiency is a treatable cause of neurologic dysfunction in infants.

Cobalamin supplementation improves motor development and regurgitations in infants: results from a randomized intervention study

BACKGROUND

During infancy, minor developmental delays and gastrointestinal complaints are common, as is a biochemical profile indicative of impaired cobalamin status.

OBJECTIVE

We investigated whether cobalamin supplementation can improve development or symptoms in infants with biochemical signs of impaired cobalamin function and developmental delay or feeding difficulties.

DESIGN

Infants <8 mo of age (n = 105) who were referred for feeding difficulties, subtle neurologic symptoms, or delayed psychomotor development were assessed for cobalamin status [by the measurement of serum cobalamin, plasma total homocysteine (tHcy), and plasma methylmalonic acid (MMA)]. Infants with biochemical signs of impaired cobalamin function, defined as a plasma tHcy concentration ≥6.5 μmol/L (n = 79), were enrolled in a double-blind, randomized controlled trial to receive 400 μg hydroxycobalamin intramuscularly (n = 42) or a sham injection (n = 37). Motor function [Alberta Infants Motor Scale (AIMS)] and clinical symptoms (parental questionnaire) were recorded at entry and after 1 mo.

RESULTS

During follow-up, cobalamin supplementation changed all markers of impaired cobalamin status (ie, plasma tHcy decreased by 54%, and MMA decreased by 84%), whereas no significant changes were seen in the placebo group (P < 0.001). The median (IQR) increase in the AIMS score was higher in the cobalamin group than in the placebo group [7.0 (5.0, 9.0) compared with 4.5 (3.3, 6.0); P = 0.003], and a higher proportion showed improvements in regurgitations (69% compared with 29%, respectively; P = 0.003).

CONCLUSIONS

In infants with biochemical signs of impaired cobalamin function, 1 intramuscular injection of cobalamin resulted in biochemical evidence of cobalamin repletion and improvement in motor function and regurgitations, which suggest that an adequate cobalamin status is important for a rapidly developing nervous system. This trial was registered at clinicaltrials.gov as NCT00710359 and NCT00710138.