Vitamin B (B12; also known as cobalamin) is a B vitamin that has an important role in cellular metabolism, especially in DNA synthesis, methylation and mitochondrial metabolism. Clinical B12 deficiency with classic haematological and neurological manifestations is relatively uncommon. However, subclinical deficiency affects between 2.5% and 26% of the general population depending on the definition used, although the clinical relevance is unclear. B12 deficiency can affect individuals at all ages, but most particularly elderly individuals. Infants, children, adolescents and women of reproductive age are also at high risk of deficiency in populations where dietary intake of B12-containing animal-derived foods is restricted. Deficiency is caused by either inadequate intake, inadequate bioavailability or malabsorption. Disruption of B12 transport in the blood, or impaired cellular uptake or metabolism causes an intracellular deficiency. Diagnostic biomarkers for B12 status include decreased levels of circulating total B12 and transcobalamin-bound B12, and abnormally increased levels of homocysteine and methylmalonic acid. However, the exact cut-offs to classify clinical and subclinical deficiency remain debated. Management depends on B12 supplementation, either via high-dose oral routes or via parenteral administration. This Primer describes the current knowledge surrounding B12 deficiency, and highlights improvements in diagnostic methods as well as shifting concepts about the prevalence, causes and manifestations of B12 deficiency.

Background Diabetic foot ulcer infection cause great morbidity and mortality among diabetic patients and is a major cause of lower extremity amputation worldwide. This study aimed to determine the profile of aerobic bacteria and their antibiotic sensitivity patterns in diabetic foot infections (DFI) among different Wagner's grades. Methods This study was conducted during December 2017-March 2018 in a Diabetic Center, Sudan. A total of 152 diabetic patients with different grades of foot ulcers were randomly enrolled in the study. The patients were grouped using Wagner's classification. Tissue biopsies and deep swabs were collected from the ulcers for aerobic cultures. The cultured isolates were identified using phenotypic and biochemical properties and their sensitivity to commonly used antibiotics, Colistin, Aikacin, Ciprofloxacin, Augmentin, Ceftazideme, Gentamicin, Clindamycin, Ceftriaxone Meropenum. Cotrimoxazole, Erythomycin, Oxacillin and Vancomycin. Fusidic acid, Imepenem, and Piperacillin was tested using the Kirby Bauer disk diffusion method. Results The mean age of the patients was 54.31 (SD ± 12.1) years, male to female ratio of 8: 1. The mean duration of diabetes was 14 (SD ± 8) years. The ulcers varied in duration from 1 day to 10 years. of 152 samples 181 aerobic bacteria were isolated. Cultures yielded 1-3 isolate per culture. The maximum number was isolated from grade 3 group followed by long standing ulcer LSU group 50.8% and 28% respectively. Polymicrobial infection was higher in LSU (30.4%). The isolates were mostly Gram-negative bacteria. The most frequent were proteus spp. (35.3%), S. aureus MRSA 14.4% and Coliform 12.2% respectively. The most common isolates in grade 3 were P. Mirablis, Staphylococcus and Coliform and in long standing ulcers were P. Mirablis, S. aureus MRSA and Coagulase negative staphylococcus respectively. Conclusion Gram-negative bacteria were more prevalent and the most frequent pathogens were Proteus spp. The

Aims/hypothesis This study reports the results of the first phase of a national study to determine the prevalence of diabetes and prediabetes (impaired fasting glucose and/or impaired glucose tolerance) in India. Methods A total of 363 primary sampling units (188 urban, 175 rural), in three states (Tamilnadu, Maharashtra and Jharkhand) and one union territory (Chandigarh) of India were sampled using a stratified multistage sampling design to survey individuals aged ≥20 years. The prevalence rates of diabetes and prediabetes were assessed by measurement of fasting and 2 h post glucose load capillary blood glucose. Results Of the 16,607 individuals selected for the study, 14,277 (86%) participated, of whom 13,055 gave blood samples. The weighted prevalence of diabetes (both known and newly diagnosed) was 10.4% in Tamilnadu, 8.4% in Maharashtra, 5.3% in Jharkhand, and 13.6% in Chandigarh. The prevalences of prediabetes (impaired fasting glucose and/or impaired glucose tolerance) were 8.3%, 12.8%, 8.1% and 14.6% respectively. Multiple logistic regression analysis showed that age, male sex, family history of diabetes, urban residence, abdominal obesity, generalised obesity, hypertension and income status were significantly associated with diabetes. Significant risk factors for prediabetes were age, family history of diabetes, abdominal obesity, hypertension and income status.

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Aims/hypothesis Raised maternal plasma total homocysteine (tHcy) concentrations predict small size at birth, which is a risk factor for type 2 diabetes mellitus. We studied the association between maternal vitamin B 12 , folate and tHcy status during pregnancy, and offspring adiposity and insulin resistance at 6 years. Methods In the Pune Maternal Nutrition Study we studied 700 consecutive eligible pregnant women in six villages. We measured maternal nutritional intake and circulating concentrations of folate, vitamin B 12 , tHcy and methylmalonic acid (MMA) at 18 and 28 weeks of gestation. These were correlated with offspring anthropometry, body composition (dual-energy X-ray absorptiometry scan) and insulin resistance (homeostatic model assessment of insulin resistance [HOMA-R]) at 6 years. Results Two-thirds of mothers had low vitamin B 12 (<150 pmol/l), 90% had high MMA (>0.26 μmol/l) and 30% had raised tHcy concentrations (>10 μmol/l); only one had a low erythrocyte folate concentration. Although short and thin (BMI), the 6-year-old children were relatively adipose compared with the UK standards (skinfold thicknesses). Higher maternal erythrocyte folate concentrations at 28 weeks predicted higher offspring adiposity and higher HOMA-R (both p <0.01). Low maternal vitamin B 12 (18 weeks; p=0.03) predicted higher HOMA-R in the Diabetologia (2008)

OBJECTIVE:To examine body size and fat measurements of babies born in rural India and compare them with white Caucasian babies born in an industrialised country. DESIGN: Community-based observational study in rural India, and comparison with data from an earlier study in the UK, measured using similar methods. SUBJECTS: A total of 631 term babies born in six rural villages, near the city of Pune, Maharashtra, India, and 338 term babies born in the Princess Anne Hospital, Southampton, UK. MEASUREMENTS: Maternal weight and height, and neonatal weight, length, head, mid-upper-arm and abdominal circumferences, subscapular and triceps skinfold thicknesses, and placental weight. RESULTS: The Indian mothers were younger, lighter, shorter and had a lower mean body mass index (BMI) (mean age, weight, height and BMI: 21.4 y, 44.6 kg, 1.52 m, and 18.2 kg/m 2 ) than Southampton mothers (26.8 y, 63.6 kg, 1.63 m and 23.4 kg/m 2 ). They gave birth to lighter babies (mean birthweight: 2.7 kg compared with 3.5 kg). Compared to Southampton babies, the Indian babies were small in all body measurements, the smallest being abdominal circumference (s.d. score: À2.38; 95% CI: À2.48 to À2.29) and mid-arm circumference (s.d. score: À1.82; 95% CI: À1.89 to À1.75), while the most preserved measurement was the subscapular skinfold thickness (s.d. score: À0.53; 95% CI: À0.61 to À0.46). Skinfolds were relatively preserved in the lightest babies (below the 10th percentile of birthweight) in both populations. CONCLUSIONS: Small Indian babies have small abdominal viscera and low muscle mass, but preserve body fat during their intrauterine development. This body composition may persist postnatally and predispose to an insulin-resistant state.

Reduced glomerular filtration rate defines chronic kidney disease and is associated with cardiovascular and all-cause mortality. We conducted a meta-analysis of genome-wide association studies for estimated glomerular filtration rate (eGFR), combining data across 133,413 individuals with replication in up to 42,166 individuals. We identify 24 new and confirm 29 previously identified loci. Of these 53 loci, nineteen associate with eGFR among individuals with diabetes. Using bioinformatics, we show that identified genes at eGFR loci are enriched for expression in kidney tissues and in pathways relevant for kidney development and transmembrane transporter activity, kidney structure, and regulation of glucose metabolism. Chromatin state mapping and DNase I hypersensitivity analyses across adult tissues demonstrate preferential mapping of associated variants to regulatory regions in kidney but not extra-renal tissues. These findings suggest that genetic determinants of eGFR are mediated largely through direct effects within the kidney and highlight important cell types and biologic pathways.

Background Low- and middle-income countries continue to experience a large burden of stunting; 148 million children were estimated to be stunted, around 30–40% of all children in 2011. In many of these countries, foetal growth restriction (FGR) is common, as is subsequent growth faltering in the first 2 years. Although there is agreement that stunting involves both prenatal and postnatal growth failure, the extent to which FGR contributes to stunting and other indicators of nutritional status is uncertain. Methods Using extant longitudinal birth cohorts (n = 19) with data on birth-weight, gestational age and child anthropometry (12–60 months), we estimated study-specific and pooled risk estimates of stunting, wasting and underweight by small-for-gestational age (SGA) and preterm birth. Results We grouped children according to four combinations of SGA and gestational age: adequate size-for-gestational age (AGA) and preterm; SGA and term; SGA and preterm; and AGA and term (the reference group). Relative to AGA and term, the OR (95% confidence interval) for stunting associated with AGA and preterm, SGA and term, and SGA and preterm was 1.93 (1.71, 2.18), 2.43 (2.22, 2.66) and 4.51 (3.42, 5.93), respectively. A similar magnitude of risk was also observed for wasting and underweight. Low birthweight was associated with 2.5–3.5-fold higher odds of wasting, stunting and underweight. The population attributable risk for overall SGA for outcomes of childhood stunting and wasting was 20% and 30%, respectively. Conclusions This analysis estimates that childhood undernutrition may have its origins in the foetal period, suggesting a need to intervene early, ideally during pregnancy, with interventions known to reduce FGR and preterm birth.