scholarly journals Assessment of vitamin B12 deficiency and B12 screening trends for patients on metformin: a retrospective cohort case review

2021 ◽  
pp. bmjnph-2020-000193
Author(s):  
Darby Martin ◽  
Jeet Thaker ◽  
Maria Shreve ◽  
Lois Lamerato ◽  
Kartazyna Budzynska
Keyword(s):  
Retrospective Cohort ◽  
Protective Factor ◽  
Vitamin B12 Deficiency ◽  
Older Age ◽  
Secondary Outcome ◽  
Vitamin B ◽  
Case Review ◽  
Large Hospital ◽  
Hospital System ◽  
B12 Deficiency

ObjectivesOur study investigated the use of vitamin B12 testing in a large cohort of patients on metformin and assesses appropriateness and benefits of screening recommendations for vitamin B12 deficiency.DesignThis retrospective cohort study included insured adult patients who had more than 1 year of metformin use between 1 January 2010 and 1 October 2016 and who filled at least two consecutive prescriptions of metformin to establish compliance. The comparison group was not exposed to metformin. Primary outcome was incidence of B12 deficiency diagnosed in patients on metformin. Secondary outcome was occurrence of B12 testing in the patient population on metformin. Records dated through 31 December 2018 were analysed.SettingLarge hospital system consisting of inpatient and outpatient data base.ParticipantsA diverse, adult, insured population of patients who had more than 1 year of metformin use between 1 January 2010 and 1 October 2016 and who filled at least two consecutive prescriptions of metformin.ResultsOf 13 489 patients on metformin, 6051 (44.9%) were tested for vitamin B12 deficiency, of which 202 (3.3%) tested positive (vs 2.2% of comparisons). Average time to test was 990 days. Average time to test positive for deficiency was 1926 days. Factors associated with testing were linked to sex (female, 47.8%), older age (62.79% in patients over 80 years old), race (48.98% white) and causes of malabsorption (7.11%). Multivariable logistic regression showed older age as the only factor associated with vitamin B12 deficiency, whereas African-American ethnicity approached significance as a protective factor.ConclusionsBased on our study’s findings of vitamin B12 deficiency in patients on metformin who are greater than 65 years old and have been using it for over 5 years, we recommend that physicians consider screening in these populations.

Vitamin B12 deficiency is the dominant nutritional cause of hyperhomocysteinemia in a folic acid-fortified population

2005 ◽  
Vol 43 (10) ◽  
Author(s):  
Ralph Green ◽  
Joshua W. Miller
Keyword(s):  
United States ◽  
Folic Acid ◽  
Vitamin B12 Deficiency ◽  
The United States ◽  
Community Dwelling ◽  
Vitamin B ◽  
Prevalence Rates ◽  
Total Vitamin ◽  
Folic Acid Fortification ◽  
B12 Deficiency

AbstractPrevalence rates for folate deficiency and hyperhomocysteinemia have been markedly reduced following the introduction of folic acid fortification in the United States. We report the prevalence of hyperhomocysteinemia in a population of community-dwelling elderly Latinos in the post-folic acid fortification era. We measured homocysteine, total vitamin B

Ileocaecal tuberculosis: an under-recognised cause of vitamin B12 deficiency

2018 ◽  
Vol 49 (2) ◽  
pp. 143-144
Author(s):  
Ashok Kumar Pannu ◽  
Dinesh Raja Palanisamy
Keyword(s):  
Terminal Ileum ◽  
Vitamin B12 Deficiency ◽  
Abdominal Tuberculosis ◽  
Megaloblastic Anaemia ◽  
Vitamin B ◽  
Lower Quadrant ◽  
Abdominal Tenderness ◽  
B12 Deficiency ◽  
Clinical Triad ◽  
Right Lower Quadrant

A combination of anaemia and knuckle pigmentation should always raise concern for megaloblastic anaemia. As the terminal ileum is the site of vitamin B12 absorption and also the commonest site of abdominal tuberculosis, a clinical triad of prolonged fever, knuckle pigmentation and right lower quadrant abdominal tenderness should suggest ileocaecal tuberculosis in endemic areas.

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

2018 ◽  
Vol 55 (6) ◽  
pp. 685-692 ◽  
Author(s):  
Saskia LM van Loon ◽  
Anna M Wilbik ◽  
Uzay Kaymak ◽  
Edwin R van den Heuvel ◽  
Volkher Scharnhorst ◽  
...  
Keyword(s):  
Data Mining ◽  
Vitamin B12 ◽  
Methylmalonic Acid ◽  
Vitamin B12 Deficiency ◽  
The Elderly ◽  
Vitamin B ◽  
Data Mining Approach ◽  
Number Of Patients ◽  
B12 Deficiency ◽  
The Relationship

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.

scholarly journals Homocystinuria masquerading as vitamin B12 deficiency

2012 ◽  
Vol 4 (2) ◽  
pp. 326-328
Author(s):  
M Wadhwani ◽  
S Beri ◽  
A Saili ◽  
S Garg
Keyword(s):  
Vitamin B12 ◽  
Megaloblastic Anemia ◽  
Vitamin B12 Deficiency ◽  
Interesting Case ◽  
Vitamin B ◽  
Ophthalmological Examination ◽  
Ophthalmic Manifestations ◽  
History Of ◽  
B12 Deficiency ◽  
Vitamin B 12

Background: Homocystinuria is a rare metabolic disorder charcterised by excess homocysteine in the urine. Vitamin B12 deficiency has diverse cutaneous, nervous and ophthalmic manifestations. Objective: To report a case of homocystinuria masquerading as vitamin B 12 deficiency. Case: We hereby are presenting an interesting case of a 4 year old boy who was being treated for Vitamin B 12 deficiency on the basis of history of delayed milestone, abdominal pain and hyperpigmentation of skin which was diagnosed as homocystinuria. Conclusion: It is important to carry out ophthalmological examination in every case of megaloblastic anemia if associated with blurring of vision and mental retardation.DOI: http://dx.doi.org/10.3126/nepjoph.v4i2.6554 Nepal J Ophthalmol 2012; 4 (8): 326-328

scholarly journals Vitamin B12 deficiency results in the abnormal regulation of serine dehydratase and tyrosine aminotransferase activities correlated with impairment of the adenylyl cyclase system in rat liver

2008 ◽  
Vol 99 (3) ◽  
pp. 503-510 ◽  
Author(s):  
Shuhei Ebara ◽  
Motoyuki Nakao ◽  
Mayuko Tomoda ◽  
Ryoichi Yamaji ◽  
Fumio Watanabe ◽  
...  
Keyword(s):  
Adenylyl Cyclase ◽  
Rat Liver ◽  
Vitamin B12 Deficiency ◽  
Tyrosine Aminotransferase ◽  
Vitamin B ◽  
Deficient Diet ◽  
Adenylyl Cyclase System ◽  
Serine Dehydratase ◽  
B12 Deficiency ◽  
Induced Changes

The aim of the present study was to elucidate the mechanism of the vitamin B12 deficiency-induced changes of the serine dehydratase (SDH) and tyrosine aminotransferase (TAT) activities in the rat liver. When rats were maintained on a vitamin B12-deficient diet, the activities of these two enzymes in the liver were significantly reduced compared with those in the B12-sufficient control rats (SDH 2·8 (sd 0·56) v. 17·5 (sd 6·22) nmol/mg protein per min (n 5); P < 0·05) (TAT 25·2 (sd 5·22) v. 41·3 (sd 8·11) nmol/mg protein per min (n 5); P < 0·05). In the B12-deficient rats, the level of SDH induction in response to the administration of glucagon and dexamethasone was significantly lower than in the B12-sufficient controls. Dexamethasone induced a significant increase in TAT activity in the primary culture of the hepatocytes prepared from the deficient rats, as well as in the cells from the control rats. However, a further increase in TAT activity was not observed in the hepatocytes from the deficient rats, in contrast to the cells from the controls, when glucagon was added simultaneously with dexamethasone. The glucagon-stimulated production of cAMP was significantly reduced in the hepatocytes from the deficient rats relative to the cells from the control rats. Furthermore, the glucagon-stimulated adenylyl cyclase activity in the liver was significantly lower in the deficient rats than in the controls. These results suggest that vitamin B12 deficiency results in decreases in SDH and TAT activities correlated with the impairment of the glucagon signal transduction through the activation of the adenylyl cyclase system in the liver.

Ischemic strokes secondary to vitamin B12 deficiency-induced hyperhomocystinemia

Neurology ◽  
1998 ◽  
Vol 51 (2) ◽  
pp. 622-624 ◽  
Author(s):  
LaRoy P. Penix
Keyword(s):  
Mean Corpuscular Volume ◽  
Serum Vitamin ◽  
Vitamin B12 Deficiency ◽  
Vitamin B ◽  
Loading Test ◽  
Schilling Test ◽  
B12 Deficiency ◽  
Recurrent Strokes ◽  
Methionine Loading Test

A 45-year-old woman sustained two ischemic cerebral infarctions 16 years after ileal resection for Crohn's disease. Her evaluation showed an elevated random serum homocystine level, a low serum vitamin B12 level, and an increased mean corpuscular volume (MCV) without anemia. A methionine-loading test resulted in a marked increase in the homocystine levels 2, 4, and 6 hours after the load. A Schilling test demonstrated a malabsorption of vitamin B12. Vitamin B12 injections normalized her fasting homocystine level and her MCV. She has had no recurrent strokes during a year follow-up.

A review of the cut-off points for the diagnosis of vitamin B12 deficiency in the general population

2015 ◽  
Vol 53 (8) ◽  
Author(s):  
Raquel Aparicio-Ugarriza ◽  
Gonzalo Palacios ◽  
Monika Alder ◽  
Marcela González-Gross
Keyword(s):  
General Population ◽  
Vitamin B12 ◽  
Vitamin B12 Deficiency ◽  
Vitamin B ◽  
B12 Deficiency

AbstractVitamin B

scholarly journals Vitamin B 12 Assay – are we on Track?

2020 ◽  
Vol 2 (8) ◽  
pp. 01-03
Author(s):  
Rateesh Sareen
Keyword(s):  
Vitamin B12 ◽  
Vitamin B12 Deficiency ◽  
Reference Interval ◽  
Population Characteristics ◽  
Vitamin B ◽  
B12 Deficiency ◽  
Vitamin B 12 ◽  
Work Up

Vitamin B12 assay is one of the most frequently ordered tests particularly as a part of regular medical checkups. The deficiency is rampant in vegetarian population. It is of immense importance that laboratories establish their own reference interval (RI) of analyte specially Vitamin B12 as a diagnosis of Vitamin B12 deficiency based on RI of kit insert inadvertently leads to unnecessary treatment or work up. A blind reliance on RI of kit insert should be discouraged as they do not take into account population characteristics and do not truly reflect RI specific to the population under study.

scholarly journals Identification of vitamin B12 deficiency in vegetarian Indians

2018 ◽  
Vol 119 (6) ◽  
pp. 629-635 ◽  
Author(s):  
Sadanand Naik ◽  
Namita Mahalle ◽  
Vijayshri Bhide
Keyword(s):  
Predictive Value ◽  
Characteristic Curve ◽  
Clinical Signs ◽  
Serum Vitamin ◽  
Vitamin B12 Deficiency ◽  
Diagnostic Value ◽  
Total Serum ◽  
Vitamin B ◽  
B12 Deficiency ◽  
Specific Uptake

AbstractThe prevalence of a sub-clinical vitamin B12 deficiency in the vegetarians is high. Total serum vitamin B12 concentration alone does not reliably reflect vitamin B12 status. Holotranscobalamin (holo-TC) II is a bioactive B12 fraction promoting specific uptake of B12 by cells and the circulating concentration reflects the intake of B12, whereas total homocysteine (tHcy) indicates the metabolic ability. In this study, we investigated the diagnostic value of circulating holo-TC, B12, folate and homocysteine in vegetarians who were at risk of B12 deficiency. B12-related biomarkers were measured in 119 young, healthy graduate vegetarians. None was folate deficient. As per reported definition, half were B12 deficient; 70 % of males and 50 % of females had low plasma holo-TC concentrations; and 92 % of males and half of females had hyperhomocysteinaemia. None had any clinical signs of B12 deficiency. Receiver operating characteristic curve analysis demonstrated similar AUC at the B12 concentration of 100 and 150 pmol/l when holo-TC (0·777 and 0·784) and homocysteine (0·924 and 0·928) were used as variables. Cut-off value of 100 pmol/l resulted in the highest sensitivity of 77·78 % and specificity of 71·05 % with a predictive value of 19·6 pmol/l for holo-TC and a sensitivity of 82·72 % and specificity of 89·7 % with a predictive value of 21·7 µmol/l for homocysteine. The combination of B12, holo-TC and tHcy improves the diagnostic accuracy at these cut-offs, and we suggest that for the young Indian vegetarians the cut-off for plasma B12 and holotrancobalamin is 100 pmol/l and 19·6 pmol/l, respectively, and for homocysteine it is 17·6 (females) and 27 µmol/l (males) for identifying B12 deficiency.

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