Prevalence Of Cobalamin Deficiency Research Articles

What is the cobalamin status among vegetarians and vegans in Australia?

Water-soluble vitamin B12 (cobalamin) plays a vital role in normal blood function and neurological functioning. Clinical and subclinical B12 deficiency has been notably reported in vegans, vegetarians, the elderly and metformin-treated diabetics. Currently, the prevalence of cobalamin deficiency among vegans and vegetarians in Australia is lacking; data on dietary intake including supplements and nutritional status are also limited. The increasing multiculturalism of Australia has seen an influx of imported foods, of which some may contain considerable vitamin B12. However, values for such foods are not included in the food composition databases. This review highlights the need to update the food composition database with culturally diverse foods containing vitamin B12. Moreover, the need for assessing dietary intakes and status using the most current best evidence and best practice on nutritional indicators (biochemical and functional biomarkers) to estimate the risk of deficiency and/or depletion is discussed.

The prevalence of cobalamin deficiency among vegetarians assessed by serum vitamin B12: a review of literature.

The prevalence of cobalamin deficiency among vegetarians assessed by serum vitamin B12: a review of literature

The prevalence of cobalamin deficiency among vegetarians assessed by serum vitamin B12: a review of literature

Individuals following vegetarian diets are at risk for developing vitamin B12 deficiency owing to suboptimal intake. As vitamin B12 is essential for the synthesis of nucleic acids, erythrocytes and in the maintenance of myelin, deficiency may result in a variety of symptoms. Some of these symptoms may be severe while others may be irreversible. The objective of this review was to assess vitamin B12 deficiency, based on reported serum vitamin B12, among individuals adhering to different types of vegetarian diets. A systematic literature search was carried out using multiple search engines including PubMed, Medline, CINAHL plus, ERIC, Nursing and Allied Health Collection and Nursing/Academic Edition. The inclusion criteria consisted of original studies that assessed serum vitamin B12, studies written in English, non-case studiesand studies that reported actual percentages of vitamin B12 deficiency. Forty research studies were included. The deficiency prevalence among infants reached 45%. The deficiency among the children and adolescents ranged from 0 to 33.3%. Deficiency among pregnant women ranged from 17 to 39%, dependent on the trimester. Adults and elderly individuals had a deficiency range of 0-86.5%. Higher deficiency prevalence was reported in vegans than in other vegetarians. Thus, with few exceptions, the reviewed studies documented relatively high deficiency prevalence among vegetarians. Vegans who do not ingest vitamin B12 supplements were found to be at especially high risk. Vegetarians, especially vegans, should give strong consideration to the use of vitamin B12 supplements to ensure adequate vitamin B12 intake. Vegetarians, regardless of the type of vegetarian diet they adhere to, should be screened for vitamin B12 deficiency.

Cobalamin and Folate Status in 6 to 35 Months Old Children Presenting with Acute Diarrhea in Bhaktapur, Nepal

BackgroundCobalamin and folate are essential micronutrients and are important in DNA and RNA synthesis, cell proliferation, growth, hematopoiesis, and cognitive function. However, data on cobalamin and folate status are lacking particularly from young children residing in low and middle income countries.ObjectiveTo measure cobalamin and folate status and identifies their predictors among 6 to 35 months old children presenting with acute diarrhea.DesignThis was a cross-sectional study in 823 children presenting with acute diarrhea. We measured plasma cobalamin, folate, methylmalonic acid and total homocysteine who sought treatment for acute diarrhea between June 1998 and August 2000.ResultsThe mean (SD) plasma concentrations of cobalamin, folate, total homocysteine and methylmalonic acid were 206 (124) pmol/L, 55 (32) nmol/L, 11.4 (5.6) µmol/L and 0.79 (1.2) µmol/L, respectively. The prevalence of low plasma cobalamin (<150 pmol/L) was 41% but less than 2% (15) children had low folate concentration (<10 nmol/L). Plasma homocysteine and methylmalonic acid concentrations were negatively associated with cobalamin concentration but not associated with folate status. The prevalence of cobalamin deficiency was higher in breastfed than non-breastfed children (44% vs 24%; p = <0.001). The prevalence of hyperhomocysteinemia (>10 µmol/L) and elevated methylmalonic acid (>0.28 µmol/L) were 73% and 52%, respectively. In the regression analyses, the plasma cobalamin concentration was positively associated with age, and introduction of animal or formula milk.ConclusionsOur study indicated that poor cobalamin status was common particularly among breastfed children. Folate deficiency was virtually none existent. Possible consequences of cobalamin deficiency in young children need to be explored.

Prevalence of cobalamin deficiency in Afyonkarahisar elderly population

Objectives To determine whether there was an increased prevalence of low serum cobalamin concentrations in elderly people. Design and Methods Serum concentrations of cobalamin were measured in 202 elderly people. Results In the elderly group, cobalamin concentrations less than 191 pg/mL were found in 79 subjects (39.1%) compared with 24.5% of 19–40 years old subjects (n = 527) and 29.7% of 41–64 years old subjects (n = 1100) (p Conclusion The prevalence of cobalamin deficiency was 39.1% in Afyonkarahisar elderly population. Many elderly people with low serum cobalamin concentration had not had hematological findings.

Homocysteine

The authors of the much publicized though not yet published Norwegian Vitamin Study (NORVIT)1 of vitamin therapy in coronary artery disease, are widely quoted as saying that vitamin therapy for lowering plasma total homocysteine (tHcy) was harmful, and that “homocysteine is dead.” However, the slides of their presentation1 do not show the B12 status of the participants, nor do they indicate whether B12 injections were given to participants with low levels of B12. Commentators2 have called NORVIT “the largest trial to date to test the hypothesis that folate supplementation reduces risk of cardiovascular disease,” but because there were 4 treatment arms in NORVIT, each with 900 participants, the number of patients randomized to folate/B12 or folate/B12/B6 was essentially the same as that in the Vitamin Intervention for Stroke Prevention (VISP) trial3 (≈1800). They used a much higher dose of B6 than other studies and cannot exclude the possibility that their results were driven by that choice. As did VISP, they also used a dose of B12 that, as has recently become apparent, was too low for adequate absorption of B12 in elderly subjects (discussed below). In this issue of Stroke , a substudy of the Vitamins to Prevent Stroke (VITATOPS) trial4 reports that in Singapore, treatment with 2.5 mg folic acid, 0.5 mg vitamin B12, and 25 mg B6 reduced levels of tHcy by 3.8 μmol/L compared with placebo.5 The authors also studied 2 polymorphism …

Prevalence of cobalamin deficiency in the Framingham elderly population

To determine whether the increased prevalence of low serum cobalamin concentrations in elderly people represents true deficiency, serum concentrations of cobalamin and folate and of metabolites that are sensitive indicators of cobalamin deficiency were measured in 548 surviving members of the original Framingham Study cohort. Serum cobalamin concentrations < 258 pmol/L were found in 222 subjects (40.5%) compared with 17.9% of younger control subjects (P < 0.001). Serum methylmalonic acid and total homocysteine concentrations were markedly elevated in association with cobalamin values < 258 pmol/L in 11.3% and 5.7%, respectively, of the cohort. Both metabolites were increased in 3.8% of the cohort, associated with significantly lower erythrocyte counts and higher mean cell volumes. Serum metabolites correlated best with serum cobalamin values, even when subnormal determinations were excluded. The prevalence of cobalamin deficiency was > or = 12% in a large sample of free-living elderly Americans. Many elderly people with "normal" serum vitamin concentrations are metabolically deficient in cobalamin or folate.

High Prevalence of Cobalamin Deficiency in Elderly Outpatients

To measure the prevalence of cobalamin (vitamin B12) deficiency in geriatric outpatients as documented by both low serum cobalamin levels and elevations of serum methylmalonic acid and homocysteine and to determine the response to cobalamin treatment. Prospective study screening elderly subjects for cobalamin deficiency using radiodilution cobalamin assays as well as stable isotope dilution gas chromatography-mass spectrometry methylmalonic acid and homocysteine assays. In patients with serum cobalamin levels < or = 300 pg/mL, the response to cobalamin treatment in the group with levels of methylmalonic acid and/or homocysteine > 3 standard deviations (SD) above the mean for normals was compared with that of those without such elevations. Outpatient geriatric clinics at the VA Medical Center and University Health Sciences Center, Denver, CO. One-hundred and fifty-two consecutive outpatients, ages 65 to 99, were screened. Twenty-nine subjects with serum cobalamin levels < or = 300 pg/mL were prospectively evaluated and treated with cobalamin. Cobalamin, methylmalonic acid, homocysteine, complete blood counts, neurologic examination, and neuropsychological testing. The prevalence of cobalamin deficiency as defined by a serum cobalamin level < or = 300 pg/mL and levels of serum methylmalonic acid and/or homocysteine elevated to > 3 SD was 14.5% of the screened outpatients. A similar proportion of patients with low normal serum cobalamin levels (between 201 and 300 pg/mL) demonstrated elevated metabolites > 3 SD (56%) compared with patients with low serum cobalamin levels (< or = 200 pg/mL) (62%). Cobalamin therapy caused a marked fall or complete correction of the elevated methylmalonic acid and homocysteine levels in each patient who was treated prospectively. Results for complete blood count, lactate dehydrogenase, bilirubin, baseline neurologic score, and baseline neuropsychologic scores did not differ in the group of patients with elevated metabolites compared with those with normal metabolites. The mean red cell volume fell significantly in the patients with elevated metabolites after 6 months of cobalamin treatment. One patient with elevated metabolites had marked improvement in his neurologic abnormalities after 6 months of cobalamin treatment. There was a high (14.5%) prevalence of cobalamin deficiency as demonstrated by elevations in serum methylmalonic acid and homocysteine in addition to low or low normal serum cobalamin levels in elderly outpatients. The serum cobalamin level was insensitive for screening since similar numbers of patients with low normal serum cobalamin levels of 201-300 pg/mL compared with patients with low cobalamin levels (< or = 200 pg/mL) had markedly elevated metabolites which fell with cobalamin treatment. Additional studies will be required to define the full clinical benefit from treatment with Cbl in elderly subjects.