Screening for cobalamin deficiency in geriatric outpatients: prevalence and influence of synthetic cobalamin intake

Methylmalonic acid in aging and disease

Metabolic byproducts have conventionally been disregarded as waste products without functions. In this opinion article, we bring to light the multifaceted role of methylmalonic acid (MMA), a byproduct of the propionate metabolism pathway mostly commonly known as a clinical biomarker of vitamin B12 deficiency. MMA is normally present at low levels in the body, but increased levels can come from different sources, such as vitamin B12 deficiency, genetic mutations in enzymes related to the propionate pathway, the gut microbiota, and aggressive cancers. Here, we describe the diverse metabolic and signaling functions of MMA and discuss the consequences of increased MMA levels, such as during the aging process, for several age-related human pathologies.

Vitamin B12 deficiency: correction of P-methylmalonic acid for estimated glomerular filtration rate to improve diagnostic value - a confirmatory study

Objectives: For diagnosis of vitamin B12 deficiency, plasma methylmalonic acid (P-MMA) is considered superior to plasma vitamin B12 (P-B12). Reduced kidney function elevates P-MMA, hence, hampering P-MMA as a biomarker. We assessed whether correcting P-MMA for estimated glomerular filtration rate (eGFR) can affect the estimated prevalence of B12 deficiency. Methods: We included 115,245 patients with concomitant measurements of P-MMA, P-B12 and P-Creatinine. B12 deficiency was classified using P-MMA decision limits at >0.75 and >0.43 µmol/L. The non-linear relation between eGFR and P-MMA was estimated using spline regression. We calculated the percentage-wise reclassification of B12 deficiency by using an eGFR corrected P-MMA formula with eGFR reference points of 90 and 60 mL/min. Results: 6% with B12 deficiency were reclassified as non-deficient after adjusting for eGFR (reference point eGFR 90 mL/min) with both P-MMA decision limits. Overall B12 deficiency prevalence was reduced from 9.6% to 9.0% (P-MMA decision limit 0.43 µmol/L). With P-MMA decision limits at 0.75 and 0.43 µmol/L, 33.6% and 44.8% of B12 deficient patients with an eGFR <60 mL/min were reclassified as non-deficient. Conclusions: We have demonstrated that correcting P-MMA for eGFR can reclassify P-MMA levels across decision limits for diagnosing B12 deficiency, in particular for patients with reduced kidney function. This may have clinical implications for avoiding overdiagnosis of this chronic disease.

Daily supplementation of a multiple micronutrient powder improves folate but not thiamine, riboflavin, or vitamin B12 status among young Laotian children: a randomized controlled trial

PURPOSE

To assess the effects of intervention with a daily multiple micronutrient powder (MNP) on thiamine, riboflavin, folate, and B₁₂ status among young Laotian children.

METHODS

Children (n = 1704) aged 6-23 mo, participating in a double-blind placebo-controlled randomized trial were individually randomized to receive daily either MNP (containing 0.5 mg of thiamine, 0.5 mg riboflavin, 150 μg folic acid, and 0.9 μg vitamin B₁₂ along with 11 other micronutrients) or placebo and followed for ~ 36 weeks. In a randomly selected sub-sample of 260 children, erythrocyte thiamine diphosphate (eThDP), plasma folate and B₁₂ concentrations, and erythrocyte glutathione reductase activation coefficient (EGRac; riboflavin biomarker) were assessed at baseline and endline.

RESULTS

There was no treatment effect on endline eThDP concentrations (110.6 ± 8.9 nmol/L in MNP vs. 109.4 ± 8.9 nmol/L in placebo group; p = 0.924), EGRac (1.46 ± 0.3 vs. 1.49 ± 0.3; p = 0.184) and B₁₂ concentrations (523.3 ± 24.6 pmol/L vs. 515.9 ± 24.8 pmol/L; p = 0.678). Likewise, the prevalence of thiamine, riboflavin, and B₁₂ deficiencies did not differ significantly between the two groups. However, endline folate concentration was significantly higher in the MNP compared to the placebo group (28.2 ± 0.8 nmol/L vs 19.9 ± 0.8 nmol/L, respectively; p < 0.001), and correspondingly, the prevalence of folate deficiency was significantly lower in the MNP group (1.6% vs 17.4%; p = 0.015).

CONCLUSIONS

Compared to a placebo, daily MNP for 9 months increased only folate but not thiamine, riboflavin, or B₁₂ status in young Laotian children.

TRIAL REGISTRATION

The trial was registered at www.

CLINICALTRIALS

gov (NCT02428647) on April 29 2015.

High folic acid or folate combined with low vitamin B-12 status: potential but inconsistent association with cognitive function in a nationally representative cross-sectional sample of US older adults participating in the NHANES

BACKGROUND

Potential safety concerns relative to impaired cognitive function may exist when high folic acid exposures are combined with low vitamin B-12 status.

OBJECTIVES

We aimed to examine the relation of the coexistence of high folate and low vitamin B-12 status with cognitive function, utilizing various definitions of "high" folate status.

METHODS

Cross-sectional data from older adults (≥60 y; n = 2420) from the 2011-2014 NHANES were analyzed. High folate status was defined as unmetabolized serum folic acid (UMFA) > 1 nmol/L or serum total folate > 74.1 nmol/L, and low vitamin B-12 status as methylmalonic acid > 271 nmol/L or serum vitamin B-12 < 150 pmol/L. Logistic regression models estimated ORs of scoring low on 1 of 4 cognitive tests: the Digit Symbol Substitution Test (DSST), the Consortium to Establish a Registry for Alzheimer's Disease Delayed Recall (CERAD-DR) and Word Learning tests, and the Animal Fluency test (AF).

RESULTS

A significant interaction was observed relative to scoring low on the DSST (<34; UMFA; P-interaction = 0.0071) and AF (serum folate; P-interaction = 0.0078) for low vitamin B-12 and high folate status. Among those with low vitamin B-12, high UMFA or high serum total folate was associated with higher risk of scoring low on the DSST (OR: 2.16; 95% CI: 1.05, 4.47) and the AF (OR: 1.93; 95% CI: 1.08, 3.45). Among those with "normal" vitamin B-12, higher UMFA or serum total folate was protective on the CERAD-DR. In noninteraction models, when high folate and normal vitamin B-12 status was the reference group, low vitamin B-12 combined with high UMFA was associated with greater risk based on the DSST (<34, OR: 2.87; 95% CI: 1.85, 4.45; <40, OR: 2.22; 95% CI: 1.31, 3.75) and AF (OR: 1.97; 95% CI: 1.30, 2.97); but low vitamin B-12 and lower UMFA (OR: 1.69; 95% CI: 1.16, 2.47) was also significantly associated for DSST < 40 risk.

CONCLUSIONS

Low vitamin B-12 was associated with cognitive impairment both independently and in an interactive manner with high folate for certain cognitive performance tests among older adults.

The Revised D-A-CH-Reference Values for the Intake of Vitamin B12 : Prevention of Deficiency and Beyond

SCOPE

The nutrition societies of Germany, Austria, and Switzerland are the joint editors of the "D-A-CH reference values for nutrient intake", which are revised regularly.

METHODS AND RESULTS

By reviewing vitamin-B12 -related biomarker studies, the reference values for vitamin B12 were revised in 2018. For adults, the estimated intake is based on the adequate serum concentrations of holotranscobalamin and methylmalonic acid. The estimated values for children and adolescents are extrapolated from the adult reference value by considering differences in body mass, an allometric exponent, and growth factors. For infants below 4 months of age, an estimated value is set based on the vitamin B12 intake via breast milk. The reference values for pregnant and lactating women consider the requirements for the fetus and for loss via breast milk. The estimated values for vitamin B12 intake for infants, children, and adolescents range from 0.5 to 4.0 µg d-1 . For adults, the estimated values are set at 4.0 µg d-1 , and for pregnant and lactating women, they are set at 4.5 and 5.5 µg d-1 , respectively.

CONCLUSION

Based on the data of several vitamin B12 status biomarkers studies, the reference value for vitamin B12 intake for adults is raised from 3.0 to 4.0 µg d-1 .

Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency

BACKGROUND

Vitamin B₁₂ deficiency is common, and the incidence increases with age. Most people with vitamin B₁₂ deficiency are treated in primary care with intramuscular (IM) vitamin B₁₂. Doctors may not be prescribing oral vitamin B₁₂ formulations because they may be unaware of this option or have concerns regarding its effectiveness.

OBJECTIVES

To assess the effects of oral vitamin B₁₂ versus intramuscular vitamin B₁₂ for vitamin B₁₂ deficiency.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and LILACS, as well as the WHO ICTRP and ClinicalTrials.gov. The latest search date was 17 July 2017. We applied no language restrictions. We also contacted authors of relevant trials to enquire about other published or unpublished studies and ongoing trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing the effect of oral versus IM vitamin B₁₂ for vitamin B₁₂ deficiency.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our primary outcomes were serum vitamin B₁₂ levels, clinical signs and symptoms of vitamin B₁₂ deficiency, and adverse events. Secondary outcomes were health-related quality of life, acceptability to patients, haemoglobin and mean corpuscular volume, total homocysteine and serum methylmalonic acid levels, and socioeconomic effects. We used GRADE to assess the quality of the evidence for important outcomes. We did not perform meta-analyses due to the small number of included trials and substantial clinical heterogeneity.

MAIN RESULTS

Three RCTs met our inclusion criteria. The trials randomised 153 participants (74 participants to oral vitamin B₁₂ and 79 participants to IM vitamin B₁₂). Treatment duration and follow-up ranged between three and four months. The mean age of participants ranged from 38.6 to 72 years. The treatment frequency and daily dose of vitamin B₁₂ in the oral and IM groups varied among trials. Only one trial had low or unclear risk of bias across all domains and outcome measures. Two trials reported data for serum vitamin B₁₂ levels. The overall quality of evidence for this outcome was low due to serious imprecision (low number of trials and participants). In two trials employing 1000 μg/day oral vitamin B₁₂, there was no clinically relevant difference in vitamin B₁₂ levels when compared with IM vitamin B₁₂. One trial used 2000 μg/day vitamin B₁₂ and demonstrated a mean difference of 680 pg/mL (95% confidence interval 392.7 to 967.3) in favour of oral vitamin B₁₂. Two trials reported data on adverse events (very low-quality evidence due to risk of performance bias, detection bias, and serious imprecision). One trial stated that no treatment-related adverse events were seen in both the oral and IM vitamin B₁₂ groups. One trial reported that 2 of 30 participants (6.7%) in the oral vitamin B₁₂ group left the trial early due to adverse events. Orally taken vitamin B₁₂ showed lower treatment-associated costs than IM vitamin B₁₂ in one trial (low-quality evidence due to serious imprecision). No trial reported on clinical signs and symptoms of vitamin B₁₂ deficiency, health-related quality of life, or acceptability of the treatment scheme.

AUTHORS' CONCLUSIONS

Low quality evidence shows oral and IM vitamin B₁₂ having similar effects in terms of normalising serum vitamin B₁₂ levels, but oral treatment costs less. We found very low-quality evidence that oral vitamin B₁₂ appears as safe as IM vitamin B₁₂. Further trials should conduct better randomisation and blinding procedures, recruit more participants, and provide adequate reporting. Future trials should also measure important outcomes such as the clinical signs and symptoms of vitamin B₁₂ deficiency, health related-quality of life, socioeconomic effects, and report adverse events adequately, preferably in a primary care setting.

Effect of physical activity on levels of homocysteine, folate, and vitamin B12 in the elderly

OBJECTIVES

Homocysteine (Hcy) has emerged as a risk factor for cardiovascular diseases (CVD). However the relationship of physical activity (PA) with Hcy levels in the elderly is controversial. Accordingly, the current study examined the effect of low and high participation in PA on serum Hcy in young (n = 77; 18-50 years) and old (n = 207; > 65 years) males (n = 141) and females (n = 142).

METHODS

Level of PA was obtained in a 1-to-1 interview and participants divided into low and high groups. Serum Hcy, folate, and vitamin B12 were obtained after 12 hour fast drawn by venipuncture.

RESULTS

Levels of Hcy correlated with folate (r = -0. 5; p = 0.000) and vitamin B12 (r = -0.3; p = 0.000). The ANOVA revealed a main effect of PA for Hcy (p = 0.04) but not for folate (p = 0.2) and vitamin B12 (p = 0.2). Main effects were found also of age for Hcy (p = 0.000) and folate (p = 0.005) as well as of gender for Hcy (p = 0.000) and vitamin B12 (p = 0.000). Subsequent ANCOVA showed lower levels of Hcy in the participants with greater versus lower PA even after controlling for B12 vitamin.

CONCLUSION

These results confirm the importance of the vitamins for regulating Hcy levels. Additionally, the data suggests that PA affects Hcy levels without affecting and independent of B vitamins in the elderly.

Multivitamin Use and Serum Vitamin B12 Concentrations in Older-Adult Metformin Users in REGARDS, 2003-2007

Metformin, an insulin-sensitizing drug, is a first line treatment for type 2 diabetes. Long-term use of metformin has been associated with subsequent reductions in vitamin B12 concentrations. The objective of our study was to determine whether metformin use is associated with lower serum vitamin B12 concentrations in older adults, and whether concurrent use of multivitamins modifies this association. We examined 2,510 participants aged 50 years and over, participating in the national population-based Reasons for Geographic And Racial Differences in Stroke (REGARDS) Study. Multivariable linear and logistic regression models were used to assess associations between multivitamin use and serum vitamin B12 concentrations. We estimated adjusted odds ratios (aOR)s and confidence intervals (CI)s. Results were stratified by three metformin/diabetes sub-groups: 1) participants with diabetes who were metformin users; 2) participants with diabetes who were not metformin users; and 3) participants without diabetes. We found that diabetic metformin users had significantly lower geometric mean serum B12 concentrations (409 pmol/L) than the group with diabetes not taking metformin (485 pmol/L; P<0.01), and the group without diabetes (445 pmol/L; P = 0.02). The geometric mean serum B12 concentrations were greater for multivitamin users (509 pmol/L) compared to those who did not use multivitamins (376 pmol/L; p<0.01). Among the participants with diabetes who were on metformin therapy, multivitamin use was associated with geometric mean serum vitamin B12 concentrations that were 50% (or 161 pmol/L) higher, compared to those not using multivitamins. Among metformin users, multivitamin use was associated with lower prevalence of combined low and borderline vitamin B12 concentrations (aOR = 0.14; 95% CI = 0.04, 0.54) compared to those not using multivitamins. In conclusion, metformin use was associated with lower geometric mean serum vitamin B12 concentrations among diabetic older adults compared to their counterparts. Concurrent multivitamin use may potentially protect against low or borderline vitamin B12 concentrations in long-term metformin users. Additional research is needed to further examine this association as low or borderline vitamin B12 concentrations can be preventable, or treatable if detected at an early stage, in long-term metformin users.

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

Vitamin B12 deficit is one of the most common vitamin deficiencies. However, there is no consensus on the cut-off points for vitamin B12 and its co-markers, such as folate, holotranscobalamin, methylmalonic acid and homocysteine. In order to establish the state of the art about cut-off points used to determine vitamin B12 deficiency in the last decades, the database MEDLINE was used for searching studies published in adults between December 1992 and May 2014 (69 articles), using search terms like 'vitamin B12', 'cobalamin', 'cut-off', 'deficiency' alone or in combinations. Broad ranges of cut-off points for vitamin B12 and its biomarkers were identified: vitamin B12 ranged between 100 pmol/L and 350 pmol/L, holotranscobalamin 20-50 pmol/L, methylmalonic acid 0.210-0.470 μmol/L, homocysteine 10-21.6 μmol/L, serum folate 3.7-15.9 nmol/L and red blood cell 124-397 nmol/L. For the majority of studies, the potential influence of age, analytical methods, gender and fortified food consumption was not taken in account when choosing cut-off values. This could explain the discrepancies between studies on vitamin B12 and folate deficiency prevalences. We conclude that there is inconsistency in the literature regarding vitamin B12 cut-offs. It would be necessary to establish different reference cut-offs according to age, considering the analytical methods used.

Vitamin B12 Deficiency Induced by the Use of Gastric Acid Inhibitors: Calcium Supplements as a Potential Effect Modifier

OBJECTIVE

Use of gastric acid inhibitors has emerged as a risk factor of vitamin B12 deficiency, especially in older adults. Calcium supplements could be an effect modifier of this relationship by its role in the absorption process of vitamin B12. The aim of this study is to examine whether the use of calcium supplements could be an effect modifier of the association between gastric acid inhibitors and vitamin B12 deficiency.

DESIGN

Cross-sectional study based on medical chart reviews.

SETTING

Geriatric Assessment Unit (GAU) of a university-affiliated hospital.

PARTICIPANTS

The study included 172 patients discharged from the GAU between 2008 and 2012.

MEASUREMENTS

Cases of vitamin B12 deficiency were identified as those who had received a diagnosis of vitamin B12 deficiency, and/or were receiving a treatment for vitamin B12 deficiency. Use of gastric acid inhibitors and calcium supplements at admission was determined from the pharmacist report. Associations between medications and vitamin B12 status were investigated using logistic regression models.

RESULTS

Seventy-one patients (41%) had vitamin B12 deficiency. At admission, 42% were taking gastric acid inhibitors and 45% calcium supplements. After adjustment for covariates, analyses revealed that vitamin B12 deficiency was more likely among users of gastric acid inhibitors who did not concomitantly received calcium supplements [OR=3.12; P=0.01]. Conversely, no significant association was observed in patients using both, gastric acid inhibitors and calcium supplements [OR=1.30; P=0.59].

CONCLUSIONS

The present study provides the very first evidence that the use of calcium supplements could be an effect modifier of the association between gastric acid inhibitors and vitamin B12 deficiency. Failure to consider calcium supplements as an effect modifier could have led to biased risk estimates in previous published studies.

B-vitamin status and bone mineral density and risk of lumbar osteoporosis in older females in the United States

BACKGROUND

Previous data suggest that elevated serum total homocysteine (tHcy) may be a risk factor for bone fracture and osteoporosis. Nutritional causes of elevated tHcy are suboptimal B-vitamin status. To our knowledge, this is the first nationally representative report on the relation of B vitamins and bone health from a population with folic acid fortification.

OBJECTIVE

The purpose of this analysis was to examine the relation between B-vitamin status biomarkers and bone mineral density (BMD), risk of osteoporosis, and biomarkers of bone turnover.

DESIGN

We examined the relation of tHcy, methylmalonic acid (MMA), and serum/red blood cell folate and total-body and lumbar spine BMD in women aged ≥50 y participating in the NHANES 1999-2004 (n = 2806), a nationally representative cross-sectional survey. These are the only years with concurrent measurement of tHcy and whole-body dual-energy X-ray absorptiometry. We also examined B-vitamin biomarkers relative to bone turnover markers, bone alkaline phosphatase, and urinary N-terminal cross-linked telopeptide of type I collagen in a 1999-2002 subset with available data (n = 1813).

RESULTS

In comparison with optimal concentrations, women with elevated tHcy were older with lower serum vitamin B-12, red blood cell folate, and dietary micronutrient intakes and had significantly higher mean ± SE markers of bone turnover (bone alkaline phosphatase: 15.8 ± 0.59 compared with 14.0 ± 0.25 μg/L; urinary N-terminal cross-linked telopeptide of type I collagen: 48.2 ± 2.9 compared with 38.9 ± 0.90 nmol bone collagen equivalents per mmol creatinine/L). Elevated MMA (OR: 1.88; 95% CI: 1.10, 3.18) and tHcy (OR: 2.17; 95% CI: 1.14, 4.15) were related to increased risk of lumbar osteoporosis. When examined as a continuous variable, tHcy was negatively associated, serum folates were positively associated, and MMA and vitamin B-12 were not significantly associated with lumbar and total-body BMD.

CONCLUSION

In this nationally representative population of older US women with high exposure to B vitamins through food fortification and dietary supplements, only elevated tHcy and MMA were independently associated with risk of lumbar spine osteoporosis.

Determining Functional Vitamin B12 Deficiency in the Elderly

BACKGROUND

Elevated concentration of serum total homocysteine usually occurs in vitamin B-12 deficiency. This metabolite can be measured and used for screening functional vitamin B-12 deficiency.

OBJECTIVES

We assessed functional vitamin B12 deficiency in Tehranian elderly admitted to elderly research center, University of Social Welfare and Rehabilitation Sciences.

PATIENTS AND MATERIALS

A cross-sectional study was performed on 232 elderly admitted to elderly research center in Tehran, Iran in 2012. According to other studies, individuals were classified into two groups: high risk of vitamin B-12 deficiency (< 220 pmol/L) and borderline vitamin B-12 (220-258 pmol/L) accompanied by elevated homocysteine (> 15 micmol/L).

RESULTS

Cut-off of 15.0 pmol/L for homocysteine was identified for persons with normal or elevated concentrations. Among persons aged 65-74 and ≥ 75 years, respectively, 56% and 93% were at high risk of vitamin B-12 deficiency.

CONCLUSIONS

The prevalence of B12 deficiency was higher in this study compared to other studies, so more attention and massive efficacious policy should be designed to reduce the deficiency of this vitamin.

Frequency of dementia syndromes with a potentially treatable cause in geriatric in-patients: analysis of a 1-year interval

In addition to neurodegenerative and vascular causes of dementia, in the differential diagnosis potentially reversible conditions of dementia also must be assessed. Routine laboratory parameters and neuroimaging, which are recommended for the differential diagnosis of suspected dementia by the German S3 Guideline "Dementia", were retrospectively studied in 166 geriatric patients with suspected dementia. Delirium was diagnosed in six patients (3.6%). These six patients were excluded from the study. Of the 160 remaining patients, there were 99 (59.6%) with an already known dementia. In this subgroup of patients, we found a potentially treatable cause of dementia in 18.2%. In the remaining 61 patients (36.8%), the newly diagnosed dementia syndrome was established according to ICD-10 criteria. Potentially reversible causes of the dementia syndrome were found in 19 of these patients (31.1%). The most common cause was depressive pseudodementia in eight patients followed by vitamin B12 deficiency in six patients. A significant amount of our patients showed laboratory or imaging changes suggestive of potentially reversible causes of the dementia syndrome upon admission. The results of our study indicate the importance of careful differential diagnosis of dementia based on the recommendations of guidelines. Although therapy of these potential causes is not always accompanied by a full recovery, the identification and therapy of treatable causes of cognitive deficits are possible even for general practitioners, who often are the primary contact persons of affected individuals.

Genetic Associations with Plasma B12, B6, and Folate Levels in an Ischemic Stroke Population from the Vitamin Intervention for Stroke Prevention (VISP) Trial

Background: B vitamins play an important role in homocysteine metabolism, with vitamin deficiencies resulting in increased levels of homocysteine and increased risk for stroke. We performed a genome-wide association study (GWAS) in 2,100 stroke patients from the Vitamin Intervention for Stroke Prevention (VISP) trial, a clinical trial designed to determine whether the daily intake of high-dose folic acid, vitamins B₆, and B₁₂ reduce recurrent cerebral infarction.

Methods: Extensive quality control (QC) measures resulted in a total of 737,081 SNPs for analysis. Genome-wide association analyses for baseline quantitative measures of folate, Vitamins B₁₂, and B₆ were completed using linear regression approaches, implemented in PLINK.

Results: Six associations met or exceeded genome-wide significance (P ≤ 5 × 10⁻⁰⁸). For baseline Vitamin B₁₂, the strongest association was observed with a non-synonymous SNP (nsSNP) located in the CUBN gene (P = 1.76 × 10⁻¹³). Two additional CUBN intronic SNPs demonstrated strong associations with B₁₂ (P = 2.92 × 10⁻¹⁰ and 4.11 × 10⁻¹⁰), while a second nsSNP, located in the TCN1 gene, also reached genome-wide significance (P = 5.14 × 10⁻¹¹). For baseline measures of Vitamin B₆, we identified genome-wide significant associations for SNPs at the ALPL locus (rs1697421; P = 7.06 × 10⁻¹⁰ and rs1780316; P = 2.25 × 10⁻⁰⁸). In addition to the six genome-wide significant associations, nine SNPs (two for Vitamin B₆, six for Vitamin B₁₂, and one for folate measures) provided suggestive evidence for association (P ≤ 10⁻⁰⁷).

Conclusion: Our GWAS study has identified six genome-wide significant associations, nine suggestive associations, and successfully replicated 5 of 16 SNPs previously reported to be associated with measures of B vitamins. The six genome-wide significant associations are located in gene regions that have shown previous associations with measures of B vitamins; however, four of the nine suggestive associations represent novel finding and warrant further investigation in additional populations.

Successful sublingual cobalamin treatment in a child with short-bowel syndrome

Vitamin B12 (B12) is essential for deoxyribonucleic acid synthesis, to maintain normal hematologic and neurologic functions. Studies suggest that cobalamin deficiency in children is more common than previously recognized. Main causes are decreased intake, abnormal absorption, and inborn errors of metabolism. The classic treatment for cobalamin deficiency is intramuscular administration of B12. There are no data concerning the use of alternative routes of cobalamin administration in children. This report shares the experience of sublingual administration of B12 to a patient with short-bowel syndrome and B12 malabsorption. We report the case of successful treatment of cobalamin deficiency by sublingual administration in a 9-year-old patient who had undergone intestinal resection and jejunum-colon, with anastomosis of 32 cm of residual small intestine and absence of distal jejunum and ileocecal junction. We determined a B12 deficiency because low serum cobalamin levels (<200 pg/mL) were shown in 2 consecutive tests (130 pg/mL and 170 pg/mL). The patient presented with neither clinical nor hematological manifestations. He received sublingual cobalamin preparation, 1000-mcg sublingual nuggets per day for 1 month. Normalization of serum cobalamin was obtained (790 pg/mL) after 1 month of treatment. The sublingual route of administration not only improved the quality of life of this patient by avoiding monthly painful injections but also reduced the cost of treatment and the number of hospital visits.

Vitamin B-12 and folate status in relation to decline in scores on the mini-mental state examination in the framingham heart study

OBJECTIVES

To investigate the cognitive significance of low to low-normal plasma vitamin B-12 concentrations and to shed light on the role that folate status plays in the association between vitamin B-12 status and cognitive decline.

DESIGN

Associations between plasma vitamin B-12 and folate and 8-year cognitive decline were evaluated, and the effects of interactions between vitamin B-12 status and folate status and supplemental folate use on cognitive decline were assessed.

SETTING

The Framingham Heart Study - a prospective epidemiological study.

PARTICIPANTS

Five hundred forty-nine community-dwelling individuals aged 74.8 ± 4.6.

MEASUREMENTS

Mini-Mental State Examination (MMSE), plasma folate, vitamin B-12, methylmalonic acid, homocysteine, demographic factors, and body mass index.

RESULTS

MMSE scores declined by 0.24 points per year over the 8-year follow-up period. Decline was significantly faster in cohort members in the bottom two plasma vitamin B-12 quintile categories, and no apparent cognitive advantage was associated with plasma vitamin B-12 from 187 to 256.8 pmol/L over less than 186 pmol/L. In cohort members with plasma vitamin B-12 less than 258 pmol/L, having a plasma folate concentration greater than 20.2 nmol/L was associated with an approximate 1-point per year decline, as was use of supplemental folate.

CONCLUSION

Plasma vitamin B-12 levels from 187 to 256.8 pmol/L predict cognitive decline. Furthermore, having plasma vitamin B-12 levels in this range or below in conjunction with high plasma folate or supplemental folate use predicts especially rapid cognitive decline.

Effects of chemical and physical enhancement techniques on transdermal delivery of cyanocobalamin (vitamin B12) in vitro

Vitamin B12 deficiency, which may result in anemia and nerve damage if left untreated, is currently treated by administration of cyanocobalamin via oral or intramuscular routes. However, these routes are associated with absorption and compliance issues which have prompted us to investigate skin as an alternative site of administration. Delivery through skin, however, is restricted to small and moderately lipophilic molecules due to the outermost barrier, the stratum corneum (SC). In this study, we have investigated the effect of different enhancement techniques, chemical enhancers (ethanol, oleic acid, propylene glycol), iontophoresis (anodal iontophoresis) and microneedles (soluble maltose microneedles), which may overcome this barrier and improve cyanocobalamin delivery. Studies with different chemical enhancer formulations indicated that ethanol and oleic acid decreased the lag time while propylene glycol based formulations increased the lag time. The formulation with ethanol (50%), oleic acid (10%) and propylene glycol (40%) showed the maximum improvement in delivery. Iontophoresis and microneedle treatments resulted in enhanced permeation levels compared to passive controls. These enhancement approaches can be explored further to develop alternative treatment regimens.

Monitoring of vitamin B-12 nutritional status in the United States by using plasma methylmalonic acid and serum vitamin B-12

BACKGROUND

Various definitions, criteria, tests, and cutoffs have been used to define vitamin B-12 status; however, a need exists for the systematic study of vitamin B-12 status in the United States because of concerns about high folic acid intakes and the potential for associated adverse effects.

OBJECTIVE

The objective was to determine the effect of different cutoff choices on outcomes and of the different degrees of serum vitamin B-12 status, definable by the concurrent use of a functional and circulating marker as the first steps to developing a data-based consensus on the biochemical diagnosis of vitamin B-12 deficiency.

DESIGN

Data from NHANES, a nationally representative cross-sectional survey, were examined for adults aged >19 y (mean ± SD age: 45 ± 1 y) from 1999 to 2004 (n = 12,612).

RESULTS

Commonly used cutoffs had a greater effect on prevalence estimates of low vitamin B-12 status with the use of vitamin B-12 than with the use of methylmalonic acid (MMA; 3-26% and 2-6%, respectively). A cutoff of >148 pmol/L for vitamin B-12 and of ≤210 nmol/L for MMA resulted in significant misclassifications. Approximately 1% of adults had a clear vitamin B-12 deficiency (low vitamin B-12 and elevated MMA); 92% of adults had adequate vitamin B-12 status. A high percentage of younger women characterized the group with low vitamin B-12 and normal MMA (2% of adults) and may have falsely reflected low vitamin B-12. Adults with elevated MMA (5%) only were demographically similar (ie, by age and race) to the deficient group and may have included some individuals with early vitamin B-12 deficiency.

CONCLUSIONS

These analyses indicate the challenges of assessing vitamin B-12 status when uncertainties exist about the appropriate cutoffs. Future studies should determine definable endpoints to achieve this goal.

The predictive value of vitamin B12 concentrations and hyperhomocysteinaemia for cardiovascular disease

BACKGROUND

Cardiovascular disease has been associated with both homocysteine and vitamin B12 levels. However, little information is available about the mutual relation in cardiovascular patients. The aim of this study was to assess the prevalence of vitamin B12 deficiency in patients with cardiovascular disease, and to study the correlation with homocysteine levels.

METHODS

Blood samples were taken from 229 patients who had been admitted to the Coronary Care Unit of the Heart-Lung Centre of the Radboud University Medical Centre in Nijmegen, the Netherlands. Patient demographics and clinical characteristics were assessed from medical files. Adjusted logistic regression was used to study the associations between vitamin B12, homocysteine and ischaemic heart disease.

RESULTS

In 70 patients (33%) serum vitamin B12 levels were below the lower limit of normal (<203 ng/l). Sixty-nine patients (33%) had vitamin B12 concentrations in the lower normal range (between 203 and 339 ng/l). Plasma homocysteine levels above the upper limit of normal were found in 83 out of the 229 patients (36%). Adjusted odds ratios for both vitamin B12 (0.76, 95% CI 0.44-1.30) and homocysteine (1.27, 95% CI 0.74-2.18) levels did not show a statistical association with ischaemic heart disease. No association was found between serum vitamin B12 levels and plasma homocysteine.

CONCLUSION

Our data suggest that hyperhomocysteinaemia and low serum vitamin B12 concentrations are independent and cannot be used as a diagnostic tool for ischaemic heart disease. (Neth Heart J 2007;15:291-4.).

Discovery of novel sources of vitamin b(12) in traditional korean foods from nutritional surveys of centenarians

Human longevity can be explained by a variety of factors, among them, nutritional factor would play an important role. In our study of Korean centenarians for their longevity, the apparent nutritional imbalance in the traditional semi-vegetarian diet raised a special attention, especially on vitamin B₁₂ status, supplied by animal foods. Interestingly, we found that the prevalence of vitamin B₁₂ deficient Korean centenarians was not higher compared with those from Western nations with animal-oriented traditional foods. We assumed that there might be some unveiled sources for vitamin B₁₂ in the Korean traditional foods. Screening of vitamin B₁₂ contents has revealed that some traditional soybean-fermented foods, such as Doenjang and Chunggukjang, and seaweeds contain considerable amounts of vitamin B₁₂. Taken together, it can be summarized that the traditional foods, especially of fermentation, might be evaluated for compensation of the nutritional imbalance in the vegetable-oriented dietary pattern by supplying vitamin B₁₂, resulting in maintenance of health status.

Dietary source of vitamin B(12) intake and vitamin B(12) status in female elderly Koreans aged 85 and older living in rural area

Recently, we found and analyzed vitamin B₁₂ in some Korean traditional plant foods which had not reported, yet. This study was to investigate vitamin B₁₂ intake and its dietary sources and the vitamin B₁₂ status in the very old elderly Koreans. We measured serum vitamin B₁₂ level and estimated the amounts of vitamin B₁₂ intake from different dietary sources in female elderly Koreans aged 85 and over who had consumed a relatively low animal traditional diet for the whole life. The average age of the subjects (n = 127) was 98.0 years (85-108 years). The assessment on energy and nutrient intake involved a one-day 24-hour recall, and serum vitamin B₁₂ concentration was measured by radioimmunoassay. Overall diet pattern was not different between the 85-99 yr-old group and centenarians, except centenarians were taking more dairy product. The average ratio of plant food to animal food consumption was 87.5:12.5 in weight. The average vitamin B₁₂ intake of our subjects was 3.2 µg/day, and 52.7% of subjects consumed under estimated average requirement, 2.0 µg/day. On dietary source, 67.3% of dietary vitamin B₁₂ was from meat, eggs and fishes and 30.6% was from plant foods, such as soybean-fermented foods, seaweeds, and kimchi. The average serum vitamin B₁₂ concentration was 450.5 pg/mL, and low serum vitamin B₁₂ (< 200 pg/mL) was found in 9.6% of subjects. Dietary vitamin B₁₂ intake was significantly lower in subjects with low serum vitamin B₁₂ (0.79 µg/day) than those with normal serum vitamin B₁₂ (3.47 µg/day). There were no significant difference in vitamin B₁₂ intake and its dietary sources and serum vitamin B₁₂ level between the 85-99 yr-old group and centenarians. In conclusion, several plant-origin foods including seaweed, soybean-fermented foods, and kimchi, may contribute significantly to good vitamin B₁₂ status in very old elderly Koreans.

Comparing costs of intramuscular and oral vitamin B12administration in primary care: A cost-minimization analysis

OBJECTIVE

To establish whether savings could be made by changing patients from intramuscular to high doses of oral vitamin B12 in primary care without compromising their wellbeing.

METHODS

Cost-minimization analysis from a UK perspective, using secondary data obtained from the literature available and expert opinion.

RESULTS

The cost of the resources used to treat patients with vitamin B12 deficiency with intramuscular vitamin B12 was calculated as between 55.99 pounds (83.1 Euro) and 99.99 pounds (148.5 Euro) per year. The cost of treating patients with high doses of oral vitamin B12 during the first year was between 125.55 pounds (186.5 Euro) and 248.55 pounds (369.1 Euro). However, once patients receiving intramuscular treatment had been converted to oral treatment, or in new patients treated orally from the outset, the cost was 35.55 pounds per year (52.8 Euro). One variable, home visits, had a high impact on the calculations.

CONCLUSION

Switching patients with vitamin B12 deficiency from intramuscular to high-dose oral therapy and treating patients newly diagnosed with vitamin B12 deficiency with oral vitamin B12 from the outset could save resources in the medium and long term, and in newly diagnosed patients. Savings would come particularly in the form of nursing time.

Routine determination of serum methylmalonic acid and plasma total homocysteine in Norway

OBJECTIVE

To study the total number of combined analyses of methylmalonic acid (MMA) and total plasma homocysteine (tHcy) carried out during February 1998 at the Central Laboratory of Haukeland University Hospital.

METHODS

Laboratory data and requester comments of 2917 subjects in whom MMA was requested during February 1998, were retrieved from the laboratory information system (LIS). In 2520 cases, the results from the combined analyses of MMA and tHcy were available. Requester comments were registered in the LIS in 1084 cases. Results from additional laboratory analyses were accessible in about 10%, of cases.

RESULTS

General practitioners requested MMA and tHcy on three main indications, i.e. low cobalamin, "control" and neurological symptoms. Metabolites were requested in twice as many women than men. Furthermore, MMA was requested in younger age groups of women compared with men. Plasma tHcy and MMA showed positive correlations with age and serum creatinine, and tHcy was generally 1-2 micromol/L higher in men than in premenopausal women. In cobalamin- (serum cobalamin > 300 pmol/L) and/or folate- (serum folate > 10 nmol/L) replete subjects, the average difference in MMA or tHcy according to the highest and lowest creatinine quartiles was 0.08 and 5-6 micromol/L, respectively. Different combinations of MMA and tHcy were evaluated by using a 5 x 5 matrix of predefined concentration intervals. Based on this matrix, cobalamin and folate deficiency could be excluded or the likely diagnoses proposed in 76% of cases. Cobalamin deficiency or folate deficiency was likely in about 7% and 12% of the subjects investigated, respectively.

CONCLUSIONS

A combined analysis of MMA and tHcy provides complementary diagnostic information. When interpreting MMA and tHcy values, age, gender and renal function in particular must be taken into account. Typical combinations of MMA and tHcy concentration intervals could be proposed, which could either exclude deficiency or indicate likely diagnoses and/or influence of confounders.

Relationships between low serum cobalamin concentrations and methlymalonic acidemia in cats

BACKGROUND

Serum cobalamin concentrations below reference range are a common consequence of gastrointestinal disease in cats. Serum cobalamin <or= 100 ng/L is associated with methylmalonic acidemia.

OBJECTIVES

To determine the prevalence of cobalamin deficiency, defined by elevated serum methylmalonic acid (MMA), in cats with serum cobalamin <or= 290 ng/L, and the optimum serum cobalamin concentration to predict cobalamin deficiency in cats. SAMPLE SET: Residual serum samples (n = 206) from cats with serum cobalamin <or= 290 ng/L.

METHODS

Retrospective, observational study. Serum cobalamin and folate were measured with automated assays. Serum MMA was determined by gas chromatography-mass spectrometry. Cobalamin deficiency was defined as serum MMA > 867 nmol/L. Sensitivity and specificity of serum cobalamin concentrations <or=290 ng/L for detecting MMA > 867 nmol/L were analyzed using a receiver-operator characteristic curve.

RESULTS

There was a negative correlation between serum cobalamin and MMA concentrations (Spearman's r=-0.74, P < 0.0001). The prevalence of MMA >or= 867 nmol/L in cats with serum cobalamin <or= 290 ng/L was 68.4%. Serum cobalamin <or= 160 ng/L had a 74% sensitivity and 80% specificity for detecting MMA > 867 nmol/L. No significant difference in serum folate concentrations was detected between affected and unaffected cats.

CONCLUSIONS AND CLINICAL IMPORTANCE

Elevated MMA concentrations, suggesting cobalamin deficiency, are common in cats with serum cobalamin <or= 290 ng/L. Cobalamin deficiency is clinically significant, and supplementation with parenteral cobalamin is recommended for cats with gastrointestinal disease and low serum cobalamin concentrations.

Causes and early diagnosis of vitamin B12 deficiency

INTRODUCTION

Vitamin B(12) deficiency is widespread. Among the population groups at risk are older people, vegetarians, pregnant women, and patients with renal or intestinal diseases. The neurological symptoms of vitamin B(12) deficiency are unspecific and can be irreversible. Early detection is therefore important, using the most sensitive and specific markers available.

METHODS

Selective literature review.

RESULTS AND DISCUSSION

Total serum vitamin B(12) is a late, relatively insensitive and unspecific biomarker of deficiency. Holotranscobalamin (holoTC), also known as active B(12), is the earliest laboratory parameter for B(12) deficiency, while methyl malonic acid (MMA) is a functional B(12) marker that will increase when the B(12) stores are depleted. Isolated lowering of holoTC shows B(12) depletion (negative B(12) balance), while lowered holoTC plus elevated MMA and homocysteine indicates a metabolically manifest B(12) deficiency, although there still may be no clinical symptoms. The diagnostic use of holoTC allows treatment to be instituted before irreversible neurological damage occurs. As the first clinical manifestations of vitamin B(12) deficiency are unspecific, those at risk should have their B(12) status checked regularly, every two to three years. Because no randomized controlled trials have yet been completed, the diagnostic and therapeutic measures proposed here are merely recommendations.

If high folic acid aggravates vitamin B12 deficiency what should be done about it?

The most common cause of vitamin B12 deficiency in older people is malabsorption of food-bound vitamin B12. Thus, it is suggested that the recommended daily allowance of 2.4 microg/d be met primarily with crystalline vitamin B12, which is believed to be well absorbed in individuals who have food-bound malabsorption. There is concern that high intakes of folic acid from fortified food and dietary supplements might mask the macrocytic anemia of vitamin B12 deficiency, thereby eliminating an important diagnostic sign. One recent study indicates that high serum folate levels during vitamin B12 deficiency exacerbate (rather than mask) anemia and worsen cognitive symptoms. Another study suggests that once vitamin B12 deficiency is established in subjects with food-bound malabsorption, 40 microg/d to 80 microg/d of oral crystalline vitamin B12 for 30 d does not reverse the biochemical signs of deficiency. Together, these studies provide further evidence that public health strategies are needed to improve vitamin B12 status in order to decrease the risk of deficiency and any potentially adverse interactions with folic acid.

What is an Adequate Dose of Oral Vitamin B12in Older People with Poor Vitamin B12Status?

The prevalence of vitamin B12 deficiency increases in the elderly, mainly because atrophic gastritis decreases the production of the acid and digestive enzymes needed to cleave protein-bound vitamin B12 from the natural chemical form of vitamin B12 found in meat, poultry, fish, and dairy foods. Depending on the biochemical criterion that is used, 5% to more than 20% of older adults have marginal or frank vitamin B12 deficiency. Adults over 50 years of age should meet the Recommended Dietary Allowance by consuming vitamin B12 in the crystalline form, which does not require gastric acid or enzymes for initial digestion. A recent clinical trial suggests that an oral dose of 500 microg/d of crystalline vitamin B12 is needed to reverse biochemical signs of vitamin B12 deficiency in older adults.

Effect of supplementation with cobalamin carried either by a milk product or a capsule in mildly cobalamin-deficient elderly Dutch persons

BACKGROUND

A high prevalence of cobalamin deficiency occurs in the elderly population, which may be treated orally or with injections. Little is known about the relative bioavailability of crystalline cobalamin added to food products.

OBJECTIVE

The objective was to assess the effect of supplementation with 1000 microg crystalline cobalamin, carried either by a milk product or a capsule, on cobalamin status in mildly cobalamin-deficient elderly Dutch persons.

DESIGN

Two double-blind randomized controlled intervention studies, each covering a 12-wk supplementation period, were carried out in parallel. Mildly cobalamin-deficient elderly persons (n = 112) were separately recruited for the milk and capsule trials. Mild cobalamin deficiency was defined as a cobalamin concentration between 100 and 300 pmol/L and a plasma methylmalonic acid (MMA) concentration > or = 0.30 micromol/L. Allocation to the placebo or cobalamin carrier was carried out independently in both trials.

RESULTS

In the fortified-milk group, the mean (+/-SD) increase in serum cobalamin was 250 +/- 96 pmol/L, the median (5th and 95th percentiles) decrease in plasma MMA was 0.19 (-0.76, -0.04) micromol/L, and the median decrease in plasma homocysteine was 4.0 (-7.3, 3.0) micromol/L. All changes were significantly different from those in the placebo milk group (P < 0.01). Likewise, in the cobalamin-capsule group, the mean increase in serum cobalamin was 281 +/- 136 pmol/L, the median decrease in plasma MMA was 0.18 (-2.95, 0.14) micromol/L, and the median decrease in plasma homocysteine was 1.8 (-10.6, 2.4) micromol/L; all changes were significantly different from those in the placebo capsule group (P < 0.01). No significant differences were observed between the fortified-milk and capsule groups (P > 0.40).

CONCLUSION

Crystalline cobalamin added to milk is an effective alternative to cobalamin capsules for improving cobalamin status.

The neurology of cobalamin deficiency in an elderly population in Israel

OBJECTIVES

To evaluate the neurological status in elderly subjects with cobalamin deficiency (CblD) compared with matched non-deficient subjects before and after cobalamin (Cbl) supplementation.

METHODS

Participants completed a questionnaire on activities of daily living, level of education, medical history, alcohol, nicotine, caffeine, and medication usage and prior consumption of vitamins. They underwent a detailed programmed neurological evaluation which was repeated after 6-9 months of Cbl therapy.

RESULTS

There were 113 subjects with blood Cbl < or =147 pmol/L, methylmalonic acid > or =0.24 mumol/L, and 212 nondeficient subjects (controls). The mean age of the patients and controls was 79.5 +/- 6.9 and 79.5 +/- 5.9 years, respectively. Fifty patients (44.4 %) and 56 controls (26.4%) were found to have mild sensory neuropathy (SN).When subjects with diabetes mellitus (DM) were excluded, however, only 30 (26.5%) patients and 23 (10.8 %) controls had SN. A history of confusional state was more common among the patients than among the controls (12.4 % and 3.3%, respectively) as was a low mini-mental state examination (MMSE) score (20.2% and 15.2%, respectively). No patient had clinical signs compatible with subacute combined degeneration (SCD). Supplementation of Cbl for 6-9 months did not alter the neurological findings,while the biochemical deficiency was corrected.

CONCLUSIONS

Mild SN rather than SCD is the main neurological impairment in elderly people with CblD. Short-term supplementation of CbL can correct the biochemical deficiency without affecting the neurological impairment.

Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency

BACKGROUND

Vitamin B12 deficiency is common and rises with age. Most people with vitamin B12 deficiency are treated in primary care with intramuscular vitamin B12 which is a considerable source of work for health care professionals. Several case control and case series studies have reported equal efficacy of oral administration of vitamin B12 but it is rarely prescribed in this form, other than in Sweden and Canada. Doctors may not be prescribing oral formulations because they are unaware of this option or have concerns regarding effectiveness.

OBJECTIVES

To assess the effectiveness of oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency.

SEARCH STRATEGY

Searches were undertaken of The Cochrane Library, MEDLINE, EMBASE and Lilacs in early 2005. The bibliographies of all relevant papers identified using this strategy were searched. In addition we contacted authors of relevant identified studies and Vitamin B12 research and pharmaceutical companies to enquire about other published or unpublished studies and ongoing trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) examining the use of oral or intramuscular vitamin B12 to treat vitamin B12 deficiency.

DATA COLLECTION AND ANALYSIS

All abstracts or titles identified by the electronic searches were independently scrutinised by two reviewers. When a difference between reviewers arose, we obtained and reviewed a hard copy of the papers and made decisions by consensus. We obtained a copy of all pre-selected papers and two researchers independently extracted the data from these studies using piloted data extraction forms. The whole group checked whether inclusion and exclusion criteria were met, and disagreement was decided by consensus. The methodological quality of the included studies was independently assessed by two researchers and disagreements were brought back to the whole group and resolved by consensus.

MAIN RESULTS

Two RCT's comparing oral with intramuscular administration of vitamin B12 met our inclusion criteria. The trials recruited a total of 108 participants and followed up 93 of these from 90 days to four months. High oral doses of B12 (1000 mcg and 2000 mcg) were as effective as intramuscular administration in achieving haematological and neurological responses.

AUTHORS' CONCLUSIONS

The evidence derived from these limited studies suggests that 2000 mcg doses of oral vitamin B12 daily and 1000 mcg doses initially daily and thereafter weekly and then monthly may be as effective as intramuscular administration in obtaining short term haematological and neurological responses in vitamin B12 deficient patients.

Cobalamin: a critical vitamin in the elderly

Vitamin B(12) deficiency is a common problem in elderly subjects. If a serum cobalamin level of about 150 pmol/L (200 pg/mL) is considered normal, 10-15% of the elderly are deficient. Today, however, a threshold of 220-258 pmol/L (300-350 pg/mL) is recognized as desirable in the elderly, or else sensitive markers like the blood concentration of homocysteine or methylmalonic acid (MMA) are used. Then the prevalence of cobalamin deficiency rises to up to 43%. In the elderly, this high prevalence of poor cobalamin status is predominantly caused by atrophic gastritis type B. Atrophic gastritis results in declining gastric acid and pepsinogen secretion, and hence decreasing intestinal absorption of the cobalamin protein complexes from food. About 20-50% of the elderly are affected. Furthermore, the reduced acid secretion leads to an alkalinization of the small intestine, which may result in bacterial overgrowth and thus to a further decrease of the bioavailability of the vitamin. In addition, some drugs such as proton pump inhibitors or H2 receptor antagonists inhibit the intestinal absorption of vitamin B(12). An already moderately reduced vitamin B(12) level is associated with vascular disease and neurocognitive disorders such as depression and impaired cognitive performance. Furthermore, a poor vitamin B(12) status is assumed to be involved in the development and progression of dementia (e.g., Alzheimer's dementia). This is especially observable if the folic acid status is reduced as well. Due to the insecure supply, the cobalamin status of elderly persons (>/=60 years) should be regularly controlled and a general supplementation with vitamin B(12) (>50 microg/day) should be considered.

A case-control study on adverse effects: H2 blocker or proton pump inhibitor use and risk of vitamin B12 deficiency in older adults

OBJECTIVE

Acid-suppressant drugs are commonly prescribed for elderly patients, a population in which vitamin B(12) deficiency is a common disorder. The purpose of this study was to examine the possible association between use of prescription histamine H-2 receptor antagonists (H2RA) or proton pump inhibitors (PPI) and vitamin B(12) deficiency in older adults.

STUDY DESIGN AND SETTING

This was a case-control study in a University-based geriatric primary care setting. Among patients aged 65 years or older with documented serum vitamin B(12) studies between 1990 and 1997, 53 vitamin B(12)-deficient cases were compared with 212 controls for past or current use of prescription H2RA/PPI according to information in subjects' medical records.

RESULTS

Controlling for age, gender, multivitamin use, and Helicobacter pylori infection, chronic (#10878;12 months) current use of H2RA/PPI was associated with a significantly increased risk of vitamin B(12) deficiency (OR 4.45; 95% CI 1.47-13.34). No association was found between past or short-term current use of H2RA/PPI and vitamin B(12) deficiency.

CONCLUSION

These findings support an association between chronic use of H2RA/PPI by older adults and development of vitamin B(12) deficiency. Additional studies are needed to confirm these findings.

Vitamin B12 deficiency as a worldwide problem

Pernicious anemia is a common cause of megaloblastic anemia throughout the world and especially in persons of European or African descent. Dietary deficiency of vitamin B12 due to vegetarianism is increasing and causes hyperhomocysteinemia. The breast-fed infant of a vitamin B12-deficient mother is at risk for severe developmental abnormalities, growth failure, and anemia. Elevated methylmalonic acid and/or total homocysteine are sensitive indicators of vitamin B12-deficient diets and correlate with clinical abnormalities. Dietary vitamin B12 deficiency is a severe problem in the Indian subcontinent, Mexico, Central and South America, and selected areas in Africa. Dietary vitamin B12 deficiency is not prevalent in Asia, except in vegetarians. Areas for research include intermittent vitamin B12 supplement dosing and better measurements of the bioavailability of B12 in fermented vegetarian foods and algae.

Vitamin B-12 deficiency induces anomalies of base substitution and methylation in the DNA of rat colonic epithelium

Derangements of one-carbon metabolism can directly affect the integrity of the genome by producing inappropriate uracil insertion into DNA and by altering patterns of DNA methylation. Vitamin B-12, a one-carbon nutrient, serves as a cofactor in the synthesis of precursors of biological methylation and in nucleotide synthesis. We therefore examined whether vitamin B-12 deficiency can induce these molecular anomalies in the colonic mucosa of rats. Weanling male Sprague-Dawley rats (n = 30) were divided into 2 groups and fed either a vitamin B-12-deficient diet or a similar diet containing adequate amounts of the vitamin. Rats from each group were killed at 6 and 10 wk. Uracil misincorporation into DNA was measured by GC/MS and genomic DNA methylation was measured by LC/MS. Plasma vitamin B-12 concentrations in deficient rats were below detectable limits at 6 and 10 wk; in control rats, concentrations were 0.46 +/- 0.07 and 0.42 +/- 0.10 nmol/L at those times. Although the colon total folate concentration did not differ between the groups, the proportion that was methylfolate was marginally greater in the deficient rats at 10 wk (P = 0.05) compared with control, consistent with the "methylfolate trap" that develops during vitamin B-12 deficiency. After 10 wk, the colonic DNA of the deficient rats displayed a 35% decrease in genomic methylation and a 105% increase in uracil incorporation (P < 0.05). This vitamin B-12-deficient diet, which was of insufficient severity to cause anemia or illness, created aberrations in both base substitution and methylation of colonic DNA, which might increase susceptibility to carcinogenesis.

High prevalences of vitamin B12 and folic acid deficiency in elderly subjects in Israel

The prevalences of vitamin B12 and folic acid deficiency in the general Israeli population of elders has not been assessed. We measured plasma cobalamin and folic acid concentrations in 418 subjects from four institutions for the aged, 749 subjects attending 19 geriatric day centres and 104 healthy controls. Methylmalonic acid (MMA) and/or homocysteine concentrations were determined in subjects who had a cobalamin concentration <221 pmol/l or folic acid concentration <11 nmol/l respectively. The prevalences of vitamin B12 deficiency (cobalamin <147 pmol/l and MMA > or =0.24 micromol/l), and folic acid deficiency (folic acid <11 nmol/l and homocysteine of >15 micromol/l) in subjects from day centres were 12.6% and 16.4% respectively, and in subjects from institutions 1.2% and 2.2% respectively (P < 0.001). Multiple logistic regression analysis indicated that the relative risk of living at home versus institutions for the aged was highly significant, with odds ratios (OR) of 6.8 [95% confidence interval (CI) 2.6-18.0] for vitamin B12 deficiency and 6.6 (95% CI 2.9-13.1) for folic acid deficiency. Analysis of data for day centre patients showed that folic acid deficiency was a significant risk factor of vitamin B12 deficiency (adjusted OR 3.68, 95% CI 2.27-5.98), and vitamin B12 deficiency was a significant risk of folic acid deficiency (adjusted OR 3.69, 95% CI 2.27-6.01). These data suggest that malnutrition is a major cause of the highly prevalent deficiencies of vitamin B12 and/or folic acid in elderly Israeli subjects dwelling at home.

Variation in plasma cystathionine and its relation to changes in plasma concentrations of homocysteine and methionine in healthy subjects during a 24-h observation period

BACKGROUND

Plasma cystathionine measurement may be a useful complement to total homocysteine measurement in the assessment of B vitamin status. Information on the within-person variation in cystathionine is currently sparse.

OBJECTIVE

The goal was to study the daily variation in plasma cystathionine concentrations in healthy subjects.

DESIGN

Twelve subjects (aged 22-29 y) were followed for 24 h. During the observation period, the subjects received a breakfast (containing 15-18 g protein) at 0900 and a beef dinner (containing approximately 50 g protein) at 1500. Multiple blood samples for metabolite analyses were collected during the day, and a final sample was obtained the next morning. The results are expressed as medians and interquartile ranges.

RESULTS

All subjects had normal fasting cystathionine concentrations [0.120 (0.100-0.160) micro mol/L]. Cystathionine concentrations increased significantly after breakfast, reached a maximum after 4 h of 142.4% (100.0-170.3%) of the fasting concentration, and then declined to fasting concentrations before dinner. After dinner, plasma cystathionine started to increase within 0.5 h and reached a maximum after 6 h [281.3% (194.1-351.4%) of the concentration measured before dinner]. The changes in plasma methionine and total homocysteine concentrations during the day were less pronounced.

CONCLUSION

Food intake, even of foods with low protein content, causes an increase in plasma cystathionine concentrations that is more pronounced than the concomitant changes in total homocysteine and methionine. In studies including plasma cystathionine measurement, blood sampling in the fasting state should be considered.

B vitamin status and concentrations of homocysteine and methylmalonic acid in elderly German women

BACKGROUND

Prior investigations found that elderly persons are at higher risk than are younger persons for B vitamin deficiency, which leads to elevated plasma total homocysteine (tHcy) concentrations that are associated with an increased risk for certain diseases such as coronary artery disease. To date, published data have shown decreased vitamin status and elevated tHcy among the elderly.

OBJECTIVE

We evaluated the dietary intake and the blood status of various B vitamins and tHcy and methylmalonic acid (MMA) concentrations in 178 younger (60-70-y-old) female seniors.

DESIGN

Dietary intake was assessed with a 3-d diet record. Thiamine, riboflavin, and vitamin B-6 activity coefficients of erythrocyte transketolase (EC 2.2.1.1), erythrocyte glutathione reductase (EC 1.6.4.2), and erythrocyte alpha-aspartic aminotransferase (EC 2.6.1.1) were used as functional indexes for the status of the 3 vitamins, respectively. Concentrations of serum and red blood cell folate, serum cobalamin and MMA, and plasma tHcy were measured.

RESULTS

Indexes of thiamine, pyridoxine, and cobalamin indicated insufficient status in one-third of the women, whereas tHcy and MMA concentrations were elevated in 17.4% and 9.6% of the women, respectively. An association between vitamin intake and vitamin concentration in the blood was found only for folate. The mean tHcy concentration in subjects in the lowest quartile of serum folate concentration was 23% higher than that in subjects in the highest quartile. There was no association between riboflavin and tHcy concentrations. MMA was positively correlated with age and inversely correlated with serum cobalamin concentration.

CONCLUSIONS

Even in younger, well-educated, female seniors, the prevalence of low B vitamin status and elevated plasma tHcy concentration is high. Thiamine, pyridoxine, folate, and cobalamin supplementation should be considered.

Response of elevated methylmalonic acid to three dose levels of oral cobalamin in older adults

OBJECTIVES

Because the effects of lower-dose oral cobalamin (Cbl) supplements on older people with cobalamin deficiency are not known, we determined whether oral Cbl supplements at three different dose levels would normalize elevated serum methylmalonic acid (MMA) and total homocysteine (tHcy) concentrations.

DESIGN

Sequential nonrandomized intervention study of three dose levels.

SETTINGS

Two university-based senior care clinics.

PARTICIPANTS

Twenty-three older adults (aged >/=65) with serum Cbl levels of 221 pmol/L (300 pg/mL) or lower and serum MMA greater than 271 nmol/L who had been enrolled in a previous screening study for Cbl deficiency (mean age 79 +/- 9; 17 male, 6 female; 17 white, 6 other).

INTERVENTION

Sequential daily treatment with 25 microg oral cobalamin, followed by 100 microg and 1,000 microg cobalamin each for a 6-week period.

MEASUREMENTS

Serum MMA, tHcy, and other metabolites at baseline and after each 6-week dosing interval.

RESULTS

Treatment with 25 microg and 100 microg lowered but did not normalize MMA levels in most subjects. A dose of 1,000 microg/day proved to be the most effective in lowering MMA levels to within normal limits. Serum tHcy was normalized in six of 11 subjects who had elevated tHcy pretreatment with oral Cbl alone and in one subject in combination with a multivitamin.

CONCLUSIONS

Most Cbl-deficient older people require more than 100 microg of oral Cbl to normalize serum MMA, which is a larger dose than is available in most standard multivitamins and Cbl supplements.