Vitamin C plays a major role in synthesis of collagen, carnitine and
norepinephrine besides its antioxidant activities, and role in
erythropoiesis [1]. Limited information is available on the vitamin C
nutriture among adolescent girls belonging to low socioeconomic status.
The study was carried out in Kirti Nagar slums of
West Delhi. Door-to-door survey to identify adolescent girls was carried
out in 6 out of the 10 major blocks of these slums. Apparently healthy,
unmarried non-pregnant adolescent girls were enrolled for the study.
Data on prevalence of plasma vitamin C deficiency
presented in this paper is a part of data from a large study which was
carried out to assess the effectiveness of iron and folic acid
supplementation with vitamin B12 on anemic adolescent girls
(CTRI/2011/12/002217). Ethics Committee Clearance was obtained from Lady
Irwin College, University of Delhi. The study was carried out during
January 2012 to March 2013.
A total of 1228 adolescent girls were identified, out
of which 794 volunteered for the study. Based on inclusion criteria, 775
adolescent girls were recruited. Venous blood was drawn by trained
personnel and collected in ethylene diaminetetraacetate (EDTA) vials.
The vials were then centrifuged at 1500 rpm for 10 minutes and plasma
was separated in pre-labelled eppendorf vials. The vials were
transported from the field to the laboratory in thermocol box containing
dry ice and were stored at –80°C until analysis. Estimation of plasma
vitamin C was undertaken in NABL accredited laboratory at our center.
Plasma vitamin C was analyzed spectrophotometrically as per standard
method [2]. Plasma vitamin C levels were categorized as deficient (0.2
mg/dL), suboptimal (0.2-0.49 mg/dL) or adequate (
0.5
mg/dL) [3].
Dietary intake of vitamin C was assessed using
24-hour recall method on a subsample (n=320). The data were
analyzed for the mean consumption level using ‘Dietsoft’ software based
on Nutritive Value of Indian Foods [4]. The value thus obtained was
assessed for adequacy by comparing with respective recommended dietary
intake (RDA) [5].
The mean (SD) level of vitamin C among 775 adolescent
girls (mean age 13.3 years) was 0.76 (0.45) mg/dL (95% CI: 0.73-0.79 mg/dL).
Overall, 6.3% (95% CI: 4.6%-8.0%) girls had deficient, 27.6% (95% CI:
24.4%-30.8%) had suboptimal and 66.1% had optimum levels of plasma
vitamin C. The mean (SD) dietary consumption of vitamin C was 48.3
(25.6) mg/day. When compared with RDA of 40 mg/day, approx. 50% subjects
reported more than 100% dietary adequacy, 20% reported 75-100% adequacy
and 30% had 50-75% adequacy.
On secondary analysis, no significant correlation of
plasma vitamin C levels was found with either hemoglobin concentration
(r=0.193) or serum ferritin (r=0.09).
The findings of the present study indicate that
one-third of adolescent girls subjects had either deficient or
sub-optimal levels of plasma vitamin C. Sporadic studies in the country
have indicated the prevalence of vitamin C deficiency varying widely
between 1.1% among malnourished children [6], 19.6% among Indian males
[7], 12.9% among Indian females [7] to as high as 73.9% among elderly
population [8]. A study carried out in children 6-16 years in Hyderabad
indicated 59.6% had poor vitamin C status (<30 µmol/L) [9]. Prevalence
of vitamin C deficiency (<2 µg/mL) was reported to be highest among
Indians and people of South Asian origin compared to other races, except
the Mexican population [10].
Keeping in view the fact that no national level data
is available on plasma vitamin C status among various age groups, we
recommend assessment of the status of plasma vitamin C in different age
groups from diverse geographic settings in the country.
Contributors: PGB: Planning of study, collecting
data in the field, interpretation of results and manuscript writing;
GST: Planning of study, supervising and monitoring data collection,
interpretation of results and finalizing the manuscript; RS: Collection
of blood samples in the field and laboratory analysis.
Funding: ICMR, through Senior Research
Fellowship. The content is solely the responsibility of the authors and
does not necessarily represent the official views of the ICMR.
Competing interests: None stated.
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