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203
ORIGINAL ARTICLE
Association of vitamin B12 with obesity, overweight, insulin
resistance and metabolic syndrome, and body fat composition;
primary care-based study
Davut Baltaci
1
, Ali Kutlucan
2
, Yasemin Turker
3
, Aylin Yilmaz
1
, Serkan Karacam
1
, Harun Deler
1
, Taner
Ucgun
4
, Ismail Hamdi Kara
1
1
Department of Family Medicine,
2
Department of Internal Medicine,
3
Family Medicine Office,
4
Department of Biochemistry; Duzce Univer-
sity, School of Medicine, Duzce, Turkey
Corresponding author:
Davut Baltaci
Department of Family Medicine,
School of Medicine, Duzce University
Konuralp, Duzce, 81620, Turkey
Phone: +90 380 54 213 90;
Fax: +90 380 54 213 87;
E-mail: davutbaltaci@hotmail.com
Original submission:
24 December 2012;
Revised submission:
03 January 2013;
Accepted:
24 January 2013.
ABSTRACT
Aim To investigate correlation of vitamin B12 with obesity insulin
resistance, metabolic syndrome.
Methods The cross-sectional and primary care-based study was
carried out. Anthropometric, blood pressure measurements and bi-
oelectric impedance analysis (BIA) were recorded. Vitamin B12,
folic acid, hemogram, insulin, ferritin, iron, total iron binding
capacity and other biochemical tests were assayed. The subjects
were grouped as obesity, overweight, control, metabolic syndro-
me (MetS) and insulin resistance (IR). Correlation of vitamin B12
with body mass index (BMI), IR, age, and BIA was evaluated.
Results The study enrolled 976 patients (obesity: 414, overweight:
212, and control: 351). The mean age in groups of obesity, overwe-
ight and control were 35.9 ± 8.7, 28.9 ± 6.3 and 33.1 ± 8.7, res-
pectively (p = 0.142). Vitamin B12 level was signicantly lower
in patients with obesity and overweight than healthy individuals
(178.9 ± 25.2; 219.8 ± 78.5, and 328.5 ± 120.5, p < 0.001, respecti-
vely). Vitamin B12 level was lower in patients with MetS (+/-) and
IR (+/-), but insignicant (p = 0.075 and 0.058, respectively). Si-
gnicant and negative correlation was observed between vitamin
B12 and BMI (r =-0.221, p=0.001). No signicant difference was
observed between obese male and female patients (247.8 ± 89.1
versus 235.5 ± 89.3 pg/mL, respectively, p=0.090).
Conclusion Low Vitamin B12 level was associated with obesity
and overweight, but not with insulin resistance, metabolic syndro-
me and gender. Vitamin B12 was negatively correlated only with
body mass index.
Keywords: vitamin B12, obesity, insulin resistance, bioelectric
impedance analysis
Med Glas (Zenica) 2013; 10(2):203-210
Medicinski Glasnik, Volume 10, Number 2, August 2013
204
INTRODUCTION
Obesity is a chronic and complex diseases de-
ned as an excess in body fat, and it is associated
with many medical problems (1, 2). People with
obesity are at great risk for diseases of metabo-
lic, cardiovascular, and mechanic disorders (3,
4). Due to continuous increase in prevalence,
it has become one of the most important public
health problems in the world and diseases en-
countered by family physicians in primary care
settings (5-7). In recent studies, vitamin deci-
encies, particularly vitamin D and B12, in obese
patients were reported. Vitamin B12 is required
in DNA synthesis and red blood cell. It is invol-
ved in myelination in central nervous system. Vi-
tamin B-12, also known as cobalamin, is one of
many vitamins belonging to vitamin B-complex.
It occurs naturally in some foods such as meat,
sh, shellsh and dairy products. Its absorption is
complex and involves several steps (8, 9).
Vitamin B12 deciency is often under-diagno-
sed, thus it is not routinely tested by most family
physicians and laboratory reference is not well
dened. True prevalence of vitamin B
12
decien-
cy in general population is unknown (10, 11). It
results from decreased intake, abnormal nutrient
absorption, and rare inborn disorder of vitamin
B
12
metabolism. Abnormal absorption may be
due to medications that decrease gastric acid se-
cretion, pernicious anemia, infection with giardia
lamblia, and any disruption of the ileal mucosa
such as Crohn and celiac disease (12). Although
dietary habits of obese children may be with con-
sumption of high quantity of carbohydrate and
fat and low in proteins from animal sources that
contain vitamin B12. It was suggested that obesi-
ty could impair absorption and indirectly inborn
errors of vitamin B12 metabolism. It was also re-
ported that poor dietary content, repeated short-
term restrictive diets and increased requirements
were often seen in obese adults, and thus resulted
in vitamin various deciencies (13-15).
Most studies reported on association of obesity
with iron and vitamin deciencies in children,
but, the number of studies in adults are inconsi-
derable (15,16). Some of these studies reported
that vitamin B12 deciency was associated with
obesity, while some reported that it was not asso-
ciated (17-20).
The present study aimed to investigate associati-
on between vitamin B12 deciency and patients
with obesity and overweight, metabolic syndro-
me and insulin resistance.
PATIENTS AND METHODS
The study design and population
The study was designed as a cross-sectional case
control. It was primary care-based study carried
out in a family medicine clinic between May 2011
and June 2012. The patients who were admitted
to the family medicine clinic of Duzce University,
School of Medicine, Department of Family Me-
dicine. All subjects gave oral informed consents.
The patients with diabetes mellitus, pregnancy,
pace-makers, end-stage renal disease, and chro-
nic obstructive pulmonary disease were excluded.
Also, the patients under current treatment of corti-
costeroids, metformin, vitamin supplements, and
long-term proton pump inhibitors (PPIs) used for
more than 3 months. Age-matched lean healthy
individuals were enrolled as a control group. The
study was approved by the Ethic Committee of
Duzce University, School of Medicine.
Obesity and overweight, insulin resistance and
metabolic syndrome definition
Obesity and overweight were dened as BMI ≥ 30
kg/m
2
and 24.9 < BMI < 30.0 kg/m
2
according to
the WHO criteria (21). Insulin resistance (IR) was
accepted as HOMA-IR (Homeostasis Model of
Assessment - Insulin Resistance) ≥ 2.5 (22). The
HOMA-IR was calculated by formulation: (fasting
glucose-mg/dL) x (fasting insulin-µU/mL) / 405.
Metabolic syndrome (MetS) was dened as crite-
ria recommended by the NCEP ATP III (National
Cholesterol Education Program Adult Treatment
Panel III) and considered if the subject had at least
three of the following ve criteria: waist circumfe-
rence (WC) > 102 cm (male) or > 88 cm (female);
blood triglyceride (TG) level ≥ 150 mg/dL, HDL
cholesterol (HDL-chol) < 40 mg/dL (male) or < 50
mg/dL (female), or under treatment of anti-lipid
agents; blood pressure ≥ 130/85 mm-Hg or under
treatment of anti-hypertensive agents; and fasting
blood glucose level ≥ 110 mg/dL or presence of di-
abetes mellitus (23). The MetS subgroup was for-
med with patients with obesity. IR subgroup was
formed with both obese and overweight patients.
205
Measurements of blood pressure and anthropo-
metric parameters
All measurements were taken by two family physi-
cians after adequate training in these procedures.
Blood pressure (BP) was measured in sitting po-
sition on the right arm using a sphygmomanome-
ter (Erka, Germany), after at least 5 minutes of
resting and avoiding smoking and drinks conta-
ining alcohol and caffeine. The rst appearance
and disappearance of Korotkoff sounds were used
to dene the blood pressures. Readings were re-
corded to nearest even number and mean of two
recordings 3 min interval was computed.
Waist circumference (WC) was measured with
subjects standing and wearing only underwear,
using a stadiometer crossing midway between
the lower rib margin and the iliac crest. Hip
circumference (HP) was measured at the level
of the greater trochanter. Height was measured
with stadiometer to the nearest 0.5 cm with su-
bjects barefoot, standing in erect position with
heels together and looking straight ahead. Wei-
ght was measured with a bioelectric impedance
body fat analyzer after checking for zero point
at each measurement, when subjects were wei-
ghed barefoot, standing still and without support,
in light clothing after removing belts and other
accessories and pockets. Body mass index (BMI)
was calculated by a computer as weight divided
by height squared (kg/m
2
).
Bioelectric impedance body fat analysis
A hand-to-foot single frequency biochemical im-
pedance analyzer with 50 kHz (Tanita, BF-510,
Omron, and Netherland) was used. After entering
the patients’ data such as height, age and gender
in the BIA, electrodes were placed on their hand
and foot. The subjects were fasting and were ba-
refoot wearing light clothing. All metallic acce-
ssories were removed. The patients with pace-
makers or pregnancy were excluded.
Biochemical analysis
Blood samples were taken from all subjects
between 08:00 and 10:00 after at least an 8-ho-
ur overnight fasting. All samples were assayed
within the same day when taken. Blood samples
for Hemogram test were drawn into a tube with
ethylenediaminetetraacetic acid (ETDA). Lipid
prole tests were assayed using the colorime-
tric method (Cobas 6000 C 501, Roche Diagno-
stic GmbH, and Mannheim Germany). Insulin,
Thyroid stimulating hormone, Vitamin B12 and
folic acid levels were assayed with solid-phase
2-site chemiluminescent immunometric assay, so-
lid-phase competitive chemiluminescent enzyme
immunoassay, solid-phase chemiluminescent
immunometric assay, and competitive immuno-
assay, respectively (IMMULITE 2000, Siemens
Healthcare Diagnostic, and Flanders, NJ, USA).
Low density lipoprotein-cholesterol (LDL-Chol)
was calculated using the Friedewald equation.
Vitamin B12 status
Vitamin B12 status was determined according
to criteria dened by Stabler (24). Based on
the criteria, vitamin B12 status was categorized
as three: vitamin B12 deciency if blood level
of vitamin B12 was < 200 pg/mL, as marginal
if vitamin B12 between 200-300 pg/mL and as
adequate if vitamin B12 > 300 pg/mL.
Statistical methods
The continuous variables were stated as mean ±
standard deviation (SD). The categorical variables
were stated as percentage. Normality distribution
was evaluated with Kolmogorov-Smirnow test.
All parameters in the study were normally distri-
buted. Independent continuous variables between
two groups were analyzed with Student-T test.
Independent continuous variables normally dis-
tributed between more than two groups were
analyzed with ANOVA test, Bonferroni. Correla-
tion of vitamin B12 with BMI, IR, total fat (kg)
and total fat (%) was analyzed with Pearson’s
correlation. Lineer regression analysis was used
for correlation between BMI, insulin resistance,
total fat (%) and total fat (kg). Signicance was
accepted, if p value was less than 0.05.
RESULTS
The study enrolled 976 patients, 414 with obesity
(66.9 % females and 33.1% males), 212 overwei-
ghed (67.9 % females and 32.1 % males), and 351
controls (75.4 % females and 24.6 % males) (p =
0.117). The mean age of the patients in the group
with obesity was 35.9 ± 8.7 (21-53 years-old), in the
overweight group 28.9 ± 6.3 (22-42 years-old), and
in controls 33.1 ± 8.7 (19-51 years-old) (p > 0.05).
Baltaci et al. Vitamin B12 and Obesity
Medicinski Glasnik, Volume 10, Number 2, August 2013
206
Body fat analysis with bioelectrical impedance of
patients from groups was shown. The result of in-
dividuals in the control group was signicantly di-
fferent from the patients with obesity and overwe-
ight (p<0.001 for total fat % and p<0.001 for total
fat kg). Systolic and diastolic blood pressure of
patients in control group were comparably lower
than in the obese and overweight groups (p<0.001
and p=0.003; p<0.001 and p<0.001, respectively).
Hemoglobin level (Hb) in the control group was
slightly lower than in other groups, but not signi-
cantly (12.8 ± 1.4 mg/dL, 13.2 ± 0.8 mg/dL, and
13.4 ± 2.1 mg/dL, respectively) (p > 0.05). It was
observed that insulin resistance was signicantly
higher among the patients with obesity than tho-
se with lean body and overweight (p=0.001 and
p<0.001), but there was no signicant difference
between participants with lean body and overwe-
ight (p=0.153) (Table 1).
pg/mL), respectively (p<0.001) (Table 2). Vita-
min B12 level in the overweight group was also
lower than in obese patients, but it was not signi-
cant (p>0.05). There were no signicant diffe-
rences in folic acid, ferritin, TS and MCV values
between groups (p=0.677, p=0.132, p=0.554, and
p=0.399, respectively). Vitamin B12 level was
lower in subgroups of metabolic syndrome (+/-)
and insulin resistance (+/-), but not signicant
(p=0.075 and p=0.058, respectively). The compa-
rison of other values, folic acid, ferritin, TS and
MCV between subgroups showed no statistical
signicance. Hemoglobin levels in subgroups of
metabolic syndrome and insulin resistance were
not different (Table 3, 4)
Body Mass Index Group
p*
Obesity
(n = 414)
Overweight
(n = 212)
Control
(n = 351)
Age
(years)
35.9 ± 8.7 28.9 ± 6.3 33.1 ± 8.7
0.273, 0.096,
0.976
SBP
(mm-Hg)
124.8 ± 14.3 112.2 ± 6.4 111.8 ± 8.3
0.005, <0.001,
<0.001
DBP
(mm-Hg)
81.1 ± 11.2 73.6 ± 4.8 71.9 ± 5.5
0.003, 0.001,
0.983
TG
(mg/dL)
151.2 ± 90.4 125.4 ± 58.3 88.9 ± 38.4
0.024, <0.001,
0.021
HDL
(mg/dL)
45.6 ± 10.1 56.3 ± 9.3 64.9 ± 15.5
0.001, <0.001,
0.164
LDL
(mg/dL)
106.7 ± 28.5 105.1 ± 10.7 102.9 ± 32.5
<0.001, <0.001,
0.892
BMI
(kg/m2)
37.5 ± 4.9 28.2 ± 1.6 22.1 ± 2.2
<0.001, <0.001
<0.001
FBG
(mg/dL)
98.9 ± 13.7 88.2 ± 5.1 88.9 ± 6.5
<0.001, <0.001,
0.146
Total Fat
(%)
42.6 ± 9.1 37.9 ± 3.8 23.7 ± 7.9
<0.001, <0.001,
<0.001
Total Fat
(kg)
12.2 ± 4.7 6.1 ± 0.9 3.7 ± 1.4
<0.001, <0.001
<0.001
ALT
(U/mL)
26.2 ± 15.9 16.4 ± 8.9 14.9 ± 6.9
0.030, <0.001,
0.005
AST
(IU/L)
22.3 ± 6.7 14.2 ± 5.1 19.4 ± 6.4
0.005, 0.518,
0.135
Uric acid
(mg/dL)
4.9 ± 1.5 4.5 ± 0.6 3.9 ± 0.7
< 0.001, 0.012,
0.082
IR
3.1 ± 2.1 1.3 ± 0.9 1.1 ± 0.8
0.153, < 0.001,
< 0.001
Table 1. Comparison of insulin resistance, anthropometric
and biochemical parameters in groups
* The signicance between three groups SBP, systolic blood pressure;
DPS, Diastolic Blood Pressure; TG, Triglyceride; HDL, High-density
lipoprotein; LDL, light-density lipoprotein; BMI, Body Mass Index;
FBG, Fasting Blood Glucose; ALT, Alaninaminotransferase; AST
Aspartateaminotransferase IR, Insulin Resistance;
Vitamin B12 level was signicantly lower in the
obese and overweight groups than in control gro-
up: 178.9 ± 25.2 (143.5-228 pg/mL), 219.8 ± 78.5
(124.1-498 pg/mL) and 328.5 ± 120.5 (148-540
Body Mass Index Group
p
Obesity
(n = 414)
Overweight
(n = 212)
Control
(n = 351)
Vit B12
(pg/mL)
178.9 ± 25.2 219.8 ± 78.5 328.5 ± 120.5
< 0.001,< 0.001,
0.923
Folic acid
(ng/mL)
8.8 ± 3.7 8.2 ± 4.3 7.4 ± 3.9
0.887, 0.769,
0.916
Ferritin
(pg/L)
60.1 ± 47.7 38.8 ± 19.9 33.3 ± 27.4
0.345, 0.157,
0.857
TS (%)
20.8 ± 9.2 28.1 ± 12.1 19.1 ± 9.6
0.898, 0.786,
0.992
MCV
(fL)
83.3 ± 6.5 88.7 ± 4.8 83.1 ± 6.4
0.004, 0.238,
0.064
Hb
(mg/dL)
13.4 ± 2.1 13.2 ± 0.8 12.8 ± 1.4
< 0.001, 0.005,
0.187
Table 2. Comparison of vitamin B12, folic acid and hemato-
logical values in groups
TS, Transferrin saturation; MCV, Mean Corpuscular Volume; Vit
B12, Vitamin B12; Hb, Hemoglobin;
Metabolic Syndrome Group
p
MetS (+)
(Mean ± SD)
MetS (-)
(Mean ± SD)
Vit B12 (pg/mL)
241.4 ± 83.2 238.43 ± 94.2 0.075
Folic acid (ng/mL)
8.5 ± 3.8 8.3 ± 3.7 0.677
Ferritin (pg/L)
55.8 ± 45.4 46.4 ± 38.4 0.132
TS (%)
22.3 ± 12.1 21.5 ± 11.6 0.554
MCV (fL)
83.4 ± 8.1 84.1 ± 5.6 0.554
Hb (mg/dL)
13.7 ± 1.6 13.1 ± 1.1 0.412
Table 3. Comparison of vitamin B12, folic acid and hemato-
logical values in metabolic syndrome subgroup
TS, Transferrin saturation; MCV, Mean Corpuscular Volume; Vit
B12, Vitamin B12; Hb, Hemoglobin;
Insulin Resistance Group
p
IR (+)
(Mean ± SD)
IR (-)
(Mean ± SD)
Vit B12 (pg/mL)
243.56 ± 6.14 234.59 ± 87.8 0.058
Folic acid (ng/mL)
8.8 ± 3.9 8.3 ± 3.8 0.404
Ferritin (pg/L)
45.7 ± 42.8 58.6 ± 42.9 0.052
TS (%)
22.9 ± 13.1 21.7 ± 10.1 0.376
MCV (fL)
85.3 ± 8.1 84.2 ± 6.1 0.218
Hb (mg/dL)
13.3 ± 0.8 12.9 ± 1.5 0.083
Table 4. Comparison of vitamin B12, folic acid and hemato-
logical values in insulin resistance subgroup
IR, Insulin resistance;
207
up was quite higher in control group (40.1% and
37.7 % versus 17.1 %) (p<0.001) (Table 5). When
vitamin B12 level was compared between male
and female patients with obesity, no signicant
differences were observed (males: 248.1 ± 88.7
versus females: 234.3 ± 90.7, p=0.090 in obesity;
males: 236.6 ± 89.4 versus females: 269.9 ± 75.7,
p=0.075; and males: 291.6 ± 102.3 versus fema-
les: 301.7 ± 104.3, p = 0.981) (Figure 1).
Groups
Vitamin B12 Status
p
Decient
(N, %)
Marginal
(N, %)
Adequate
(N, %)
BMI
(N = 976)
Control (N = 351)
Overweight (N = 212)
Obesity (N = 414)
60 (17.1) 154 (44.0) 137 (38.9)
<
0.001
80 (37.7 ) 88 (41.5) 44 (20.8)
166 (40.1) 166 (40.3) 82 (19.6)
MetS
(N = 414)
MetS (+) (N = 244)
MetS (-) (N = 170)
101 (41.5) 99 (40.6) 44 (18.1)
0.686
65 (38.1) 69 (40.9) 36 (21.0)
IR
(N = 626)
IR (+) (N = 314)
IR (-) (n = 312)
116 (36.8) 133 (42.4) 65 (20.8)
0.284
103 (32.9) 128 (41.1) 81 (26.0)
Table 5. Comparison of vitamin B12 status according to body
mass index, metabolic syndrome and insulin resistance
MetS, metabolic syndrome; IR, insulin resistance;
Figure 1. Comparison of vitamin B12 level between males and
females in obesity, overweight and control groups
Vitamin B12 status (decient, marginal and
adequate) was compared according to BMI,
MetS and IR groups. No signicant differences
for vitamin B12 status were observed in MetS
and IR groups (p=0.686 and p=0.284, respecti-
vely). However, signicant difference was obser-
ved between vitamin B12 status and BMI groups.
Accordingly, the percentage of patients with vita-
min B12 deciency in obese and overweight gro-
Figure 2. Correlation of vitamin B12 with BMI, IR, and body composition analysis. 2a) cor-
relation between vitamin B12 and total fat (kg) measured via bioelectric impedance analysis,
revealing significant but weak negative correlation (r = -0.090, p = 0.031); 2b) negative
and mild significant correlation between vitamin B12 and total fat (%) was demonstrated (r
=-0.230, p=0.001); 2c) moderate significant and negative correlation between itamin B12
and body mass index (r =-0.221, p=0.001); 2d) Vitamin B12 was significantly and negatively,
but weakly, correlated with insulin resistance (r =-0.078, p=0.048).
Baltaci et al. Vitamin B12 and Obesity
Medicinski Glasnik, Volume 10, Number 2, August 2013
208
Moderate signicant and negative correlation
was observed between vitamin B12 and BMI (r=
-0.221, p=0.001) but weak negative correlation
with insulin resistance, total fat (%) and total fat
(kg) was detected (r =-0.078, p=0.048; r =-0.230,
p=0.001, and r=-0.090, p=0.031, respectively) (Fi-
gures 2a, 2b, 2c, 2d). With linear regression anal-
ysis, it was found that only vitamin B12 was nega-
tively correlated with BMI: beta= -0.241, p=0.002
(95 % CI: -5.055 and -1.116), but not with age,
total fat (kg), total fat (%) and insulin resistance.
DISCUSSION
Vitamin B12 deciency is silent and common in
general population (10). Causes of Vitamin B12
deciencies are multifactorial and associated
with many health problems (8). Also, obesity is
common and its prevalence is increasing in the
world (2). Therefore, both health problems have
gained importance in family medicine practice in
the last decades.
To the best of our knowledge, the present study
was the rst study which investigated the associ-
ation of vitamin B12 with body fat analysis (total
fat % and total fat kg) in addition to BMI, IR, and
MetS in obese and overweight patients. The study
indicated that vitamin B12 deciency is common,
compared to healthy individuals. It is not more
frequent only in patients with obesity, but also in
those who are overweight. The study has shown
that vitamin B12 level was correlated only with
BMI, but not with IR, MetS, age and gender.
Vitamin B12 deciency in obesity, metabolic
syndrome and its relation with insulin resistance
was previously studied in several investigations
among Turkish population. Guven et al. (25) re-
ported that vitamin B12 level was signicantly
lower in patients with metabolic syndrome than
those without metabolic syndrome. Our study
has found that vitamin B12 level was also lower
in patients with metabolic syndrome than in the
patients with non-metabolic syndrome but not
signicantly. All patients with metabolic and
non-metabolic syndrome in our study were obe-
se, and it is the reason why we found no signi-
cant difference. Vitamin B12 and folic acid su-
pplement in patients with metabolic syndrome
improved insulin resistance and endothelial fun-
ction (26, 27). Therefore, we suggest that vita-
min B12 supplements may be better for patients
with metabolic syndrome who have decient or
marginal level of vitamin B12.
Kaya et al. conducted a study on association
between insulin resistance, obesity and vitamin
B12 in patients with polycystic ovary syndrome.
They concluded that obesity, insulin resistance
and elevated homocysteine level were associated
with vitamin B12 deciency (28). We investiga-
ted vitamin B12 deciency in general population
in the present study and found vitamin B12 corre-
lation with BMI, not with insulin resistance.
Previously reported study on the association
between vitamin B12 and obesity in middle-aged
women have shown a signicantly lower vitamin
B12 in obese women and negative
correlation
with BMI (29). The current study investigated a
correlation of vitamin B12 level with bioelectric
fat analysis in both male and female patients with
obesity and overweight, in addition to BMI, insu-
lin resistance, metabolic syndrome.
Obese people are not only at risk for vitamin
B12 deciency, but also for iron deciency. Pin-
has-Hamiel et al. (30) studied the association
between obesity/overweight and iron decien-
cy, and found that negative correlation of low
iron deciency with BMI, reporting the grea-
ter prevalence of iron deciency in obese and
overweight children and adolescents. In con-
trast, the results of this study have shown lower
but insignicant transferrin saturation and ferri-
tin level in the control group than in obese and
overweight patients.
Beside there was no signicant difference
between B12 level in males and females, male
subjects with obesity and overweight had more
vitamin B12 level, compared to female counter-
parts. In studies, various results regarding vita-
min B12 level between male and female indivi-
duals were reported (31-33).
In some studies, it was reported that vitamin B 12
deciencies were associated with long-term use
of metformin, histamine-2 blockers (H2-blocker)
and proton pump inhibitors (34,35). In our study,
the patients who had used metformin, PPIs and
H2-blocker agents for over 3 months were exc-
luded. Additionally, it was shown that helicobac-
ter pylori infection was associated with vitamin
B12 deciency in recent studies (36-38). It was
known that frequency of helicobacter pylori in-
fection and dyspeptic symptoms in obese patients
209
were common (39,41). The patients with obesity
tend to use intermittently PPIs or H2-blockers
to relieve dyspeptic complaints. Intermittent use
can also cause vitamin B12 deciency in obese
people.
There were two limitations of the study. Firstly,
our study is cross-sectional. Secondly, serum ho-
mocysteine and methylmalonic acid level were
not assayed in the study. Homocysteine and
methylmalonic acid are used for determination
of vitamin deciency. Our study was primary
care- based study, so those laboratory tests are
not routinely used and they are not cost-effective
in family medicine clinics.
In conclusion, obesity and overweight are addi-
tional risk factors for vitamin B12 deciency. In
obesity, the reason for vitamin deciency is mul-
tifactorial and modiable. The physicians, parti-
cularly family physicians, should keep in mind
that vitamin B12 level may be lower than in non-
obese people. They should check B12 level in pa-
tients with obesity and overweight, although they
are asymptomatic.
ACKNOWLEDGEMENT
We would like to thank our technicians and staff
members of biochemistry laboratory.
FUNDING
No specic funding was received for this study
TRANSPARENCY DECLARATIONS
Competing interests: none to declare.
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