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Post-gastrectomy anemia: evaluation of 72 cases with post-gastrectomy
anemia.
Hematology. 2007 Feb;12(1):81-4.
Anemia is common
in patients following gastrectomy. The purpose of this study was to
document causes of anemias developing during the post-gastrectomy
period and to determine the importance of complete blood count
parameters on types of anemia. A total of 72 patients (23 women and 49
men) who had previously undergone gastrectomy in the past and who were
admitted for the evaluation of anemia were enrolled in study. The
patients who were evaluated and treated for anemia in the post-gastrectomy
period were excluded. Iron deficiency anemia was present in 68 (94.4%)
of 72 gastrectomized patients with anemia. Deficiencies of vitamin B12
and folate were present in 57 (79.2%) and in three patients,
respectively. The most common cause of anemia was the combination of
iron and vitamin B12 deficiencies. Iron deficiency was present in the
majority of patients, followed by vitamin B12 deficiency in frequency.
In all combinations of iron deficiency, the values of mean cell
hemoglobin and mean cell hemoglobin concentration were either normal
or low. In cases who had low white blood cell and platelet counts
vitamin B12 deficiency was frequent, while in cases who had high
numbers of white cells or platelets iron deficiency was more frequent.
In conclusion, gastrectomized patients should be followed for anemia
and treated appropriately based on the cause of anemia.
Vitamin B12
and folate in non-institutionalized urban older people.Arch
Latinoam Nutr. 2006 Jun;56(2):135-40.
Vitamin B12
and folate deficiencies are the main nutritional determinants of
hyperhomocysteinemia, which is an independent risk factor for
cardiovascular diseases. There is scarce information about nutritional
status on vitamin B12 and serum levels of folate in Mexican older
people. The objective was to evaluate the nutritional status of
vitamin B12 and folic acid concentration in non-institutionalized,
urban elderly men and women subjects. One hundred volunteers over 60
years were included in this cross-sectional study. Serum levels of
vitamin B12 and folate were measured. In addition some biochemical and
anthropometric indicators were also evaluated. Considering serum
values of vitamin, 30% had vitamin B12 deficiency, 52% normal status
and 18% with high levels. None subjects had folic acid deficiency, by
the contrary, a high proportion (62%) showed elevated levels in serum.
There was an effect of sex on vitamin B12 status. Elderly men showed
significantly lower levels of vitamin B12, and it was according with
significant higher prevalence of vitamin B12 deficiency in this group
as compared with the women group. The high proportion of vitamin B12
deficiency found in this study underline a possible public health
problem and guarantee further survey-studies about vitamin B12 status
and to explore causes and consequences of the deficiency. Finally, due
the sample size and the design of the study, the results must be seen
with caution and not try to generalize.
Folate deficiency
is associated with nutritional anaemia in Lebanese women of
childbearing age.Public
Health Nutr. 2006 Oct;9(7):921-7.
OBJECTIVE: The
objective of this study was to identify the determinants of anaemia in
Lebanese women of childbearing age attending health centres in
Lebanon. DESIGN: Cross-sectional study carried out between May and
December 2003. Anthropometric measurements as well as sociodemographic,
health and dietary intake data were collected using a questionnaire.
Haemoglobin (Hb), plasma ferritin, plasma folate and vitamin B12 were
assessed using standard laboratory methods. SETTING: Governmental
health centres in Lebanon. SUBJECTS: Four hundred and seventy
non-pregnant Lebanese women aged 15-45 years. RESULTS: Anaemia (Hb <12
g dl(-1)) and iron deficiency (ferritin <15 microg l(-1)) were
prevalent in 16.0 and 27.2% of the study sample, respectively. Of the
total sample, 7.7% had iron-deficiency anaemia. The percentage of
women with either Hb or ferritin deficiency or both was 35.6%. Plasma
folate and vitamin B12 deficiency was reported in 25.1 and 39.4%,
respectively, and 12.6% of the women had both folate and vitamin B12
deficiencies. Of the anaemic group, 48.0% of the women had iron
deficiency. The intake of iron was lower in iron-deficient than in
non-deficient women and a positive relationship was shown between
folate intake and its corresponding serum levels. Regression analysis
showed that ferritin, plasma folate and family history of anaemia were
significant determinants of the anaemia in the sample of women.
CONCLUSIONS: Anaemia not related to iron deficiency was partly
explained by plasma folate deficiency. Measures to control folate and
iron deficiency should be considered.
Homocysteine,
vitamin B12 and folate levels in premature coronary artery disease.BMC
Cardiovasc Disord. 2006 Sep 26;6:38.
BACKGROUND:
Hyperhomocysteinemia is known as an independent risk factor of
atherosclerosis, but the probable role of hyperhomocysteinemia in
premature Coronary Artery Disease (CAD) is not well studied. The aim
of this study was to assess the role of hyperhomocysteinemia, folate
and Vitamin B12 deficiency in the development of premature CAD.
METHODS: We performed an analytical case-control study on 294
individuals under 45 years (225 males and 69 females) who were
admitted for selective coronary angiography to two centers in Tehran.
RESULTS: After considering the exclusion criteria, a total number of
225 individuals were enrolled of which 43.1% had CAD. The mean age of
participants was 39.9 +/- 4.3 years (40.1 +/- 4.2 years in males and
39.4 +/- 4.8 years in females). Compared to the control group, the
level of homocysteine measured in the plasma of the male participants
was significantly high (14.9 +/- 1.2 versus 20.3 +/- 1.9 micromol/lit,
P = 0.01). However there was no significant difference in homocysteine
level of females with and without CAD (11.8 +/- 1.3 versus 11.5 +/-
1.1 micromol/lit, P = 0.87). Mean plasma level of folic acid and
vitamin B12 in the study group were 6.3 +/- 0.2 and 282.5 +/- 9.1
respectively. Based on these findings, 10.7% of the study group had
folate deficiency while 26.6% had Vitamin B12 deficiency. Logistic
regression analysis for evaluating independent CAD risk factors showed
hyperhomocysteinemia as an independent risk factor for premature CAD
in males (OR = 2.54 0.95% CI 1.23 to 5.22, P = 0.01). Study for the
underlying causes of hyperhomocysteinemia showed that male gender and
Vitamin B12 deficiency had significant influence on incidence of
hyperhomocysteinemia. CONCLUSION: We may conclude that
hyperhomocysteinemia is an independent risk factor for CAD in young
patients (below 45 years old)--especially in men--and vitamin B12
deficiency is a preventable cause of hyperhomocysteinemia.
Folic acid
fortification: prevention as well as promotion of cancer.Ned
Tijdschr Geneeskd. 2006 Jul
1;150(26):1443-8.
In many
countries foods are fortified with folic acid to prevent neural-tube
defects. Beneficial effects on cancer, cardiovascular diseases and
dementia are also assumed. Fortification with folic acid is not
allowed in The Netherlands, although exemption can be granted. As well
as beneficial effects, harmful effects may also occur. In addition to
masking vitamin-B12 deficiency, there is some evidence that folic acid
may promote progression of established tumours in laboratory animals
and humans. In addition, it has been hypothesized that fortification
with folic acid may have further negative effects on cancer through
genetic selection. Given the high prevalence of cancer, these
potentially harmful effects should also be taken into account in the
Dutch debate on the advantages and disadvantages of folic acid
fortification.
Uncertain
effects of folic acid on disorders other than neural-tube defects.Ned
Tijdschr Geneeskd. 2006 Jul
1;150(26):1439-42 .
Periconceptional supplemention with folic acid prevents neural-tube
defects in infants. However, contrary to expectations, clinical trials
found no beneficial effect of folic acid on the recurrence of
cardiovascular disease. Trial evidence on folic acid and cognitive
decline or dementia is scarce, though observational studies suggest
that high folate intake may prevent these disorders. In contrast,
animal studies suggest that high doses of folic acid enhance the
growth of existing tumours. However, recent clinical trials failed to
show significant effects of folic acid on cancer incidence and
mortality. There are also speculations that folic-acid fortification
may increase the number of newborns with the thermolabile variant of
methylene tetrahydrofolate reductase. There appears to be little
evidence that folic-acid supplementation may mask vitamin-B12
deficiency. In view of these controversies, it is unlikely that The
Netherlands will mandate folic-acid fortification of staple foods in
the near future. Therefore, women who are planning a pregnancy should
be urged to take folic-acid supplements.
High frequency
of maternal vitamin B12 deficiency as an important cause of infantile
vitamin B12 deficiency in Sanliurfa province of Turkey.Eur
J Nutr. 2006 Aug;45(5):291-7.
BACKGROUND:
Vitamin B12 deficiency in infancy may cause failure to thrive, severe
neurological disorders and megaloblastic pancytopenia. It is well
known that infants born with deficient vitamin B12 storage have
increased the risk of vitamin B12 deficiency. Vitamin B12 deficiency
is more prevalent in infancy in Sanliurfa province (at the southeast
region of Turkey). AIM OF THE STUDY: The aim of this study was to
determine the frequencies of vitamin B12, folic acid and iron
deficiencies in pregnants and their babies at birth and to what extend
the mothers' deficiency becomes effective on babies' deficiencies.
METHODS: The study groups were constituted by 180 pregnant women and
their single and term babies. Venous blood samples of pregnants were
obtained 1-3 h before delivery and babies' cord bloods were collected
at birth. Vitamin B12 and folic acid levels were measured with electro
chemiluminiscence method; serum iron and iron binding capacities were
measured by colorimetric method and complete blood counts were
performed by automatic blood counter. RESULTS: Mean vitamin B12 levels
in maternal and cord blood serum were 130 +/- 61.7 pg/ml and 207 +/-
141 pg/ml; mean folic acid levels were 8.91 +/- 6.46 ng/ml and 17.8
+/- 11.8 ng/ml; mean serum iron levels were 56.9 +/- 37.5 microg/dl
and 147 +/- 43.2 microg/dl; and mean transferrin saturations were 11.8
+/- 8% and 65.6 +/- 24%, respectively. There were vitamin B12
deficiency (<160 pg/ml) in 72% of the mothers and 41% of the babies,
and severe deficiency (<120 pg/ml) in 48% of the mothers and 23% of
the babies. Folic acid deficiency was found in 12% of the mothers, but
was not found in the babies. There were iron deficiency in 62% of the
mothers and 1% of the babies. There were statistically significant
correlation between maternal and cord blood serum vitamin B12 levels
(r = 0.395, P < 0.001) and folic acid levels (r = 0.227, P = 0.017),
while there were no correlation between maternal and cord blood iron
levels and transferrin saturations. CONCLUSION: The study results
showed that vitamin B12 deficiency is prevalent in pregnants in this
region and that 41% of infants have born with deficient vitamin B12
storages. Therefore, prophylactic use of vitamin B12 by pregnant women
in Sanliurfa and other poor communities could have considerable
benefits to prevent vitamin B12 deficiency and its complications in
infants.
Folate
and vitamin B12 status of a multiethnic adult population.J
Natl Med Assoc. 2006 Jan;98(1):67-72.
BACKGROUND: Folic acid and vitamin B12 are of particular interest for
their diverse biological functions and preventive roles in many
prevalent chronic diseases. However, ethnic differences on the status
of these vitamins have not been investigated among multiethnic adult
college students. METHODS: A cross-sectional study (n = 177) was
conducted to determine the dietary intakes and levels of serum
concentrations of folate and vitamin B12 among triethnic college
students-non-Hispanic white, Hispanic and non-Hispanic black. Dietary
intake was assessed using a validated food frequency questionnaire,
and serum was analyzed for folate and vitamin B12 using standardized
methods. RESULTS: Mean intakes of both vitamins without
supplementation was higher (P < 0.05) among non-Hispanic white males
than females, and non-Hispanic white and non-Hispanic black males and
females. Non-Hispanic white females had a significantly lower mean
dietary intake of vitamin B12 than the females of other ethnic groups
(P < 0.01). There was a positive correlation between B12 intake and
serum concentrations. More than 52% of the females did not meet the
required folate intake of 400 microg/day. CONCLUSIONS: The data
suggest that there was no difference in overall mean intake of folate
and vitamin B12 or serum concentrations in regard to gender or
ethnicity. One-fourth of the female subjects failed to meet the
recommended folate intake when supplement was excluded.
The impact
of folate status and folic acid supplementation on the micronucleus
frequency in human erythrocytes.Mutat
Res. 2006 Jan 31;603(1):33-40.
Folic acid has
a well-documented stabilising effect on chromosomes. A correlation
between folate status and chromosome stability in humans has been
reported in studies that were restricted to certain subpopulations,
e.g., folate-deficient persons. The goal of the present investigation
was to clarify if there also is a correlation between folate status
and chromosome stability among individuals without any folate
deficiency. The method used here is the recently developed flow
cytometry-based micronucleus assay in human transferrin-positive
reticulocytes (MN-Trf-Ret). In a blood sample, separation of the very
young reticulocytes from the mature erythrocytes makes this
micronucleus assay possible. This investigation comprises three
studies (cross-sectional, giving baseline data), two of which are
connected to an intervention study. In the three cross-sectional
studies (total number of subjects, 99) the frequency of MN-Trf-Ret (fMN-Trf-Ret)
was measured and compared with the serum folate status. In two of the
studies also serum homocysteine and Vitamin B12 were measured and
compared with the baseline fMN-Trf-Ret. Combining the results from the
three cross-sectional studies, a negative correlation between folate
status and fMN-Trf-Ret was obtained (p<0.05). The goal of the
intervention studies was to clarify if different nutritional
supplementations had any effect on the fMN-Trf-Ret and the cell
proliferation (percentage polychromatic erythrocytes, PCE). Each of
the two studies involved two groups, one placebo and one supplemented
group. In one of the studies the supplementation was folic acid, 1000
microg/day during 1 week (n=30, both sexes); in the other intervention
study, folic acid (800 microg/day), B12 (20 microg/day) and B6 (4
mg/day) were taken during 1 week (n=29, both sexes). No significant
difference in %PCE or fMN-Trf-Ret between the two groups was found in
either of the two intervention studies.
Vitamin B12
and folate serum levels in newly admitted psychiatric patients.Clin
Nutr. 2006 Feb;25(1):60-7.
BACKGROUND &
AIMS: Deficiencies of cobalamin and folate may play a causal role in
the development or exacerbation of psychiatric illnesses. We compared
cobalamin and folate levels in newly admitted psychiatric patients to
mentally healthy controls and assessed their correlation with various
psychiatric conditions. METHODS: All patients consecutively admitted
to a psychiatric hospital were examined for serum cobalamin and folate
levels. Controls were obtained from a population with no known mental
illness. Values were considered to be below normal if cobalamin was
<223 pg/ml and folate <3.1 ng/ml. RESULTS: The 224 newly admitted
patients did not differ significantly from controls, both with regard
to the mean cobalamin level and to the prevalence of lower than normal
levels. About 30% of patients had low folate values compared to 2.5%
in the control group (P<0.0001). Mean folate level in controls was
significantly higher than in patients (P<0.0001), where a positive
correlation was found between low folate levels and depression.
CONCLUSIONS: The results of our study suggest that folate levels be
assessed in patients admitted to psychiatric wards, especially in
those with depression. Further study is needed to evaluate the role of
folate and cobalamin in psychiatric illness.
Folate and
vitamin B12 in relation to lactation: a 9-month postpartum follow-up
study.
Eur J Clin Nutr. 2006 Jan;60(1):120-8.
OBJECTIVE: To
investigate the relation between lactation and markers of folate and
vitamin B12 (B12) deficiency in women with and without vitamin
supplementation. DESIGN: A 9-month follow-up study. Subjects and
methods: Blood samples from 91 women, who gave birth to a single
healthy child, were collected 3 weeks, 4 and 9 months postpartum and
analysed for circulating level of homocysteine (tHcy), methylmalonic
acid (MMA), folate and B12. The participants were categorized as
exclusively, partly or not breast-feeding dependent on the degree of
lactation 4 months postpartum. During follow-up, lifestyle factors
were recorded by structured interviews. RESULTS: Among 72 exclusively
breast-feeding women, the median (10-90% percentile) tHcy was 5.8
(3.1-8.3) micromol/l 3 weeks postpartum, 6.1 (4.1-10.3) micromol/l 4
months postpartum and 5.3 (3.6-8.7) micromol/I 9 months postpartum. At
9 months postpartum, none of the women breast-fed exclusively. No
significant change occurred in the concentration of B12 and folate.
Exclusively breast-feeding women without vitamin supplementation had
higher median tHcy than supplemented exclusively breast-feeding women
4 and 9 months postpartum (7.0 vs 5.4 micromol/l (P < 0.001) and 5.8
vs 4.5 micromol/l (P = 0.003), respectively). Six women had increased
(>15 micromol/l) tHcy; four of these were unsupplemented and
exclusively breast-feeding. CONCLUSION: We found no overall indication
of depletion of the folate and B12 stores during the lactation period
in this population. However, folate-supplemented women had lower tHcy
and higher folate levels, suggesting a beneficial effect of
supplementation with folate throughout lactation.
High prevalence of
folic acid and vitamin B12 deficiencies in infants, children,
adolescents and pregnant women in Venezuela.Eur
J Clin Nutr. 2005 Sep;59(9):1064-70.
BACKGROUND: There is increased worldwide concern about the
consequences of folic acid and vitamin B12 deficiencies on health,
which include megaloblastic anemia, neural tube defects and
cardiovascular disease. OBJECTIVE: This study intended to determine
the prevalence of folic acid and vitamin B12 deficiencies in
vulnerable groups in labor and poor socioeconomic strata of the
Venezuelan population. METHODS: A total of 5658 serum samples were
processed to determine folic acid and vitamin B12 concentrations. The
study involved three surveys performed during 2001-2002 and included
infants, children, adolescents and pregnant women from labor and poor
socioeconomic strata of the population. The method used was a radio
immunoassay designed for the simultaneous measurement of serum folic
acid and vitamin B12. RESULTS: The prevalence of folic acid deficiency
was higher than 30% for all groups studied, reaching 81.79% in
adolescents. Vitamin B12 deficiency was 11.4% in samples collected
nationwide, but there was also a similar prevalence of high serum
levels. The prevalence of folic acid and vitamin B12 deficiencies in
pregnant women reached 36.32 and 61.34%, respectively. CONCLUSION:
This work shows that there is a high prevalence of folic acid
deficiency, especially in women of reproductive age, pregnant
adolescents and in the whole population studied in Vargas state. This
situation requires immediate intervention as supplementation or food
fortification programs.
Vitamin B12,
folic acid and mental function in the elderly.
Invest Clin.
2005 Mar;46(1):53-63.
Elderly people
is a vulnerable population group to specific nutrient deficiencies as
vitamin B12 and folic acid, which are closely related to mental
functions deterioration, especially of cognitive functions. This study
was aimed to measure B12 vitamin and folic acid indicators and to
establish relationships to mental function. 53 elderly, older than 60
years, living in a geriatric home were assessed. The dietary intake
was evaluated by the direct weighed method, serum B12 vitamin and
folic acid by radioimmunoanalysis and mental function by Foltein's
mini-mental test. Dietary intake for Vit B12 was adequate and
deficient for folic acid while serum levels were within normal range.
Vitamin B12 levels were at marginal or deficiency values in 26,4% of
the elderly and folic acid deficiency was present in 43.4%. 49% of the
elderly had mental function alterations and B12 vitamin levels were
significantly lower in this group. A positive association between age
and mental function (elderly below 80 years had lower risk of mental
impairment) and between serum B12 and mental function were found.
Elderly were at risk of deficiency for both vitamins and age and
mental function were associated to this risk. Further evaluation
including other nutrients should be performed.
Treatment of depression: time to consider folic acid and vitamin B12.J
Psychopharmacol.
2005 Jan;19(1):59-65.
We review the
findings in major depression of a low plasma and particularly red cell
folate, but also of low vitamin B12 status. Both low folate and low
vitamin B12 status have been found in studies of depressive patients,
and an association between depression and low levels of the two
vitamins is found in studies of the general population. Low plasma or
serum folate has also been found in patients with recurrent mood
disorders treated by lithium. A link between depression and low folate
has similarly been found in patients with alcoholism. It is
interesting to note that Hong Kong and Taiwan populations with
traditional Chinese diets (rich in folate), including patients with
major depression, have high serum folate concentrations. However,
these countries have very low life time rates of major depression. Low
folate levels are furthermore linked to a poor response to
antidepressants, and treatment with folic acid is shown to improve
response to antidepressants. A recent study also suggests that high
vitamin B12 status may be associated with better treatment outcome.
Folate and vitamin B12 are major determinants of one-carbon
metabolism, in which S-adenosylmethionine (SAM) is formed. SAM donates
methyl groups that are crucial for neurological function. Increased
plasma homocysteine is a functional marker of both folate and vitamin
B12 deficiency. Increased homocysteine levels are found in depressive
patients. In a large population study from Norway increased plasma
homocysteine was associated with increased risk of depression but not
anxiety. There is now substantial evidence of a common decrease in
serum/red blood cell folate, serum vitamin B12 and an increase in
plasma homocysteine in depression. Furthermore, the MTHFR C677T
polymorphism that impairs the homocysteine metabolism is shown to be
overrepresented among depressive patients, which strengthens the
association. On the basis of current data, we suggest that oral doses
of both folic acid (800 microg daily) and vitamin B12 (1 mg daily)
should be tried to improve treatment outcome in depression.
Folate, DNA
stability and colo-rectal neoplasia.Proc
Nutr Soc. 2004 Nov;63(4):571-8.
Lower
levels of dietary folate are associated with the development of
epithelial cell tumours in man, particularly colo-rectal cancer. In
the majority of epidemiological studies blood folate or reported
folate intake have been shown to be inversely related to colo-rectal
cancer risk. Folate, via its pivotal role in C1 metabolism, is crucial
both for DNA synthesis and repair, and for DNA methylation. This
function is compromised when vitamin B12 is low. Vitamin B12
deficiency has been shown to increase biomarkers of DNA damage in man
but there is no evidence directly linking low vitamin B12 with cancer.
Disturbingly, folate and vitamin B12 deficiencies are common in the
general population, particularly in the underprivileged and the
elderly. How folate and/or vitamin B12 deficiency influence
carcinogenesis remains to be established, but it is currently believed
that they may act to decrease DNA methylation, resulting in
proto-oncogene activation, and/or to induce instability in the DNA
molecule via a futile cycle of uracil misincorporation and removal.
The relative importance of these two pathways may become clear by
determining both DNA stability and cytosine methylation in individuals
with different polymorphic variants of key folate-metabolising
enzymes. 5,10-Methylenetetrahydrofolate reductase converts
5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate and thereby
controls whether folate is employed for DNA synthesis or DNA
methylation. Colo-rectal cancer risk is decreased in subjects
homozygous for a common variant (C677T) of the gene coding for this
enzyme, suggesting that DNA synthesis and repair may be 'enhanced' in
these individuals. Evidence from animal and human studies is presented
here in support of folate acting to maintain genomic stability through
both these mechanisms.
Folic acid
with or without vitamin B12 for cognition and dementia.Cochrane
Database Syst Rev. 2003;(4):CD004514.
BACKGROUND:
Folates are vitamins essential to the development of the central
nervous system. Insufficient folate activity at the time of conception
and early pregnancy can result in congenital neural tube defects. In
adult life folate deficiency has been known for decades to produce a
characteristic form of anaemia ("megaloblastic"). More recently
degrees of folate inadequacy, not severe enough to produce anaemia,
have been found to be associated with high blood levels of the amino
acid homocysteine. Such degrees of folate inadequacy can arise because
of insufficient folates in the diet or because of inefficient
absorption or metabolic utilisation of folates due to genetic
variations. Conventional criteria for diagnosing folate deficiency may
be inadequate for identifying people capable of benefiting from
dietary supplementation. High blood levels of homocysteine have been
linked with the risk of arterial disease, dementia and Alzheimer's
disease. There is therefore interest in whether dietary supplements of
folic acid (an artificial chemical analogue of naturally occurring
folates) can improve cognitive function of people at risk of cognitive
decline associated with ageing or dementia, whether by affecting
homocysteine metabolism or through other mechanisms.There is a risk
that if folic acid is given to people who have undiagnosed deficiency
of vitamin B12 it may lead to neurological damage. Vitamin B12
deficiency produces both an anaemia identical to that of folate
deficiency but also causes irreversible damage to the central and
peripheral nervous systems. Folic acid will correct the anaemia of
vitamin B12 deficiency and so delay diagnosis but will not prevent
progression to neurological damage. For this reason trials of folic
acid supplements may involve simultaneous administration of vitamin
B12. Apparent benefit from folic acid given in the combination would
therefore need to be "corrected" for any effect of vitamin B12 alone.
A separate Cochrane review of vitamin B12 and cognitive function is
being prepared. OBJECTIVES: To examine the effects of folic acid
supplementation, with or without vitamin B12, on elderly healthy and
demented people, in preventing cognitive impairment or retarding its
progress. SEARCH STRATEGY: Trials were identified from a search of the
Cochrane Dementia and Cognitive Improvement Specialized Register Group
on 9 April 2003 using the terms: folic acid, folate, vitamin B9,
leucovorin, methyltetrahydrofolate, vitamin B12, cobalamin,
cyanocobalamin, dementia, cognitive function, cognitive impairment,
Alzheimer's disease, vascular dementia, mixed dementia and controlled
trials. MEDLINE and EMBASE (both all years) were searched for
additional trials on healthy people. SELECTION CRITERIA: All
double-blind placebo-controlled randomized trials, in which
supplements of folic acid with or without vitamin B12 were compared
with placebo for elderly healthy people or people with any type of
dementia or cognitive impairment. DATA COLLECTION AND ANALYSIS: The
reviewers independently applied the selection criteria and assessed
study quality. One reviewer extracted and analysed the data. In
comparing intervention with placebo, weighted mean differences, and
standardized mean difference or odds ratios were estimated. MAIN
RESULTS: Four randomized controlled trials fulfilled the inclusion
criteria for this review. One trial (Bryan 2002) enrolled healthy
women, and three (Fioravanti 1997; Sommer 1998; VITAL 2003) recruited
people with mild to moderate cognitive impairment or dementia with or
without diagnosed folate deficiency. Fioravanti 1997 enrolled people
with mild to moderate cognitive impairment or dementia as judged by
scores on the Mini-Mental State Examination (MMSE) and Global
Deterioration Scale and with serum folate level<3ng/l. One trial
(VITAL 2003) studied the effects of a combination of vitamin B12 and
folic acid on patients with mild to moderate cognitive impairment due
to Alzheimer's disease or mixed dementia.The analysis from the
included trials found no benefit from folic acid with or without
vitamin B12 in comparison with placebo on any measures of cognition
and mood for healthy or cognitively impaired or demented people: Folic
acid effect and healthy participants: there was no benefit from of
oral 750 mcg folic acid per day for five weeks compared with placebo
on measures of cognition and mood of 19 healthy women aged 65 to 92.
Folic acid effect and people with mild to moderate cognitive decline
or dementia: there were no statistically significant results in favour
of folic acid with or without vitamin B12 on any measures of cognitive
function. Scores on the Mini-Mental State Examination (MMSE) revealed
no statistically significant benefit from 2 mg per day folic acid plus
1mg vitamin B12 for 12 weeks when compared with placebo (WMD 0.39, 95%
CI -0.43 to 1.21, P=0.35). Cognitive scores on the Alzheimer's Disease
Scale (ADAS-Cog) showed no statistically significant benefit from 2 mg
/day folic acid plus 1 mg /day vitamin B12 for 12 weeks compared with
placebo (WMD 0.41, 95% -1.25 to 2.07, P=4.63). The Bristol Activities
of Daily Living Scale (BADL) revealed no benefit from 2mg per day of
folic acid plus 1 mg vitamin B12 for 12 weeks in comparison with
placebo (WMD -0.57, 95%CI -1.95 to 0.81, P=0.42). None of the sub
tests of the Randt Memory Test (RMT) showed statistically significant
benefit from 15 mg of folic acid orally per day for 9 weeks when
compared with placebo.One trial (Sommer 1998) reported a significant
decline compared with placebo in two cognitive function tasks in
demented patients who had received high doses of folic acid (10 mg
/day) for unspecified periods. One trial (VITAL 2003) showed that 2 mg
folic acid plus 1 mg vitamin B12 daily for 12 weeks significantly
lowered serum homocysteine concentrations (P <0.0001). REVIEWER'S
CONCLUSIONS: There was no beneficial effect of 750 mcg of folic acid
per day on measures of cognition or mood in older healthy women. In
patients with mild to moderate cognitive decline and different forms
of dementia there was no benefit from folic acid on measures of
cognition or mood. Folic acid plus vitamin B12 was effective in
reducing the serum homocysteine concentrations. Folic acid was well
tolerated and no adverse effects were reported. More studies are
needed. |
