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Serum retinol and beta-carotene levels in subacute sclerosing
panencephalitis.J
Child Neurol. 2007 Mar;22(3):341-3.
Reduced serum
levels of vitamin A affect morbidity and mortality in measles. The
authors' newly diagnosed subacute sclerosing panencephalitis (n = 21)
and age-matched control groups (n = 20) had mean serum beta-carotene
levels of 1.12 +/- 0.56 and 1.50 +/- 0.52 microg/mL, respectively.
Serum retinol <20 microg/dL was observed in 6 of 21 subacute
sclerosing panencephalitis and 0 of 20 control cases (P < .05).
Vitamin A deficiency can accompany subacute sclerosing panencephalitis:
its contribution to the pathogenesis or course of the disease warrants
further investigations.
Effectiveness
of an early supplementation scheme of high-dose vitamin A versus
standard WHO protocol in Gambian mothers and infants: a randomised
controlled trial.Lancet.
2007 Jun 23;369(9579):2088-96.
BACKGROUND:
Most developing countries have adopted a standard WHO dosing schedule
for vitamin A supplementation. However, in 2002 the International
Vitamin A Consultative Group (IVACG) Annecy Accord recommended a new
high-dose regimen for mothers and infants. Our aim was to test whether
the new high-dose regimen of vitamin A supplementation would increase
maternal and infant plasma vitamin A, reduce infant Helicobacter
pylori infection and nasopharyngeal pneumococcal carriage, and improve
infant gut epithelial integrity. METHODS: In an area of moderate
vitamin A deficiency in rural Gambia, 220 mother-infant pairs were
enrolled in a randomised double-blind trial between September, 2001,
and October, 2004, that compared the IVACG high dose with the WHO
dose. The primary endpoints were levels of maternal and infant plasma
vitamin A, H pylori infection, pneumococcal carriage, and gut
epithelial integrity. The trial is registered as ISRCTN 98554309.
FINDINGS: 197 infants completed follow-up to 12 months (99 high dose
and 98 WHO dose). There were no adverse events at dosing. No
differences were found in the primary outcomes for high-dose versus
WHO schedule: maternal vitamin A concentration at 2 months +0.02
micromol/L (95% CI -0.10 to 0.15); infant vitamin A at 5 months +0.01
micromol/L (-0.06 to 0.08); H pylori infection at 12 months -0.3%
(-14.7 to 14.2); maternal pneumococcal carriage at 12 months -2.0%
(-13.7 to 9.7); infant pneumococcal carriage at 12 months -4.1% (-15.8
to 7.6); infant gut mucosal damage at 12 months 5.2% (-8.7 to 19.2).
There were more clinic attendances by the high-dose group in the first
6 months of life (p=0.018). INTERPRETATION: Our results do not lend
support to the proposal to increase the existing WHO standard dosing
schedule for vitamin A in areas of moderate vitamin A deficiency.
Caution is urged for future studies because trials have shown possible
adverse effects of higher doses of vitamin A, and potential negative
interactions with the expanded programme on immunisation (EPI)
vaccines.
Retinoid
signaling during spermatogenesis as revealed by genetic and metabolic
manipulations of retinoic acid receptor alpha.Soc
Reprod Fertil Suppl. 2007;63:11-23.
The importance
of dietary retinol (vitamin A) and retinoid signaling for normal
development and differentiation has been recognised for many years.
Vitamin A deficiency results in a variety of abnormalities, most of
which can be corrected by supplementing the diet with
all-trans-retinoic acid (ATRA), with the exception of blindness and
male sterility. ATRA, an active metabolite of vitamin A, functions
primarily by binding to nuclear receptors of the steroid hormone
superfamily, the retinoic acid receptors (RARs). Gene targeting
studies revealed the importance of ATRA signaling through the RARs for
spermatogenesis. Mice that are homozygous for a null mutation in the
gene encoding RARalpha, Rara-/-, exhibit defects in spermatogenesis
and male sterility. The abnormalities in these RARalpha-deficient
testes have been examined in detail in a series of recent studies from
our laboratory and will be summarised in this paper. We also review
how dietary, pharmacologic and genetic strategies, alone or in
combination, can be used to gain further insight into retinoid
function in mammalian spermatogenesis.
Impact of mass
supplementation of vitamin A.
Indian J Pediatr.
2007 May;74(5):443-7.
OBJECTIVE: To
study the impact of mass supplementation of Vitamin A solution on
morbidity due to diarrhea, Acute respiratory infection (ARI) and
xerophthalmia. METHODS: The two rounds of age specific mass
distribution of Vitamin A solution were undertaken during January 2000
and December 2000 respectively covering 27,642 (98.7%) and 31,762
(88.0%) children respectively out of total beneficiaries in two round
of PPI in Chandigarh. A random sample of 276 children from
intervention area and 252 children from control area in the age group
of 1-5 yr were followed up on monthly basis for morbidity pattern for
a period of nine mth. The morbidity pattern for intervention and
control area children was compared to see the impact of mass
supplementation of Vitamin A solution. RESULTS: The average annual
episodes of diarrhea in intervention children were lower (3.9 per yr)
as compared to control children (5.2 per yr) although difference was
not statistically significant (P>0.05) except in initial month. The
average annual episodes of ARI in intervention children were lower
(5.1 per yr) as compared to Control children (6.0 per yr) although
difference was not significant (P>0.05) except in initial first mth.
There was significant decline in vitamin A deficiency (VAD) as no case
of Bitot's spot was found in intervention children as compared to
control children where the prevalence of Bitot's spot ranged from
4.3-5.08% during different visits. The mortality rate was found to be
higher in control children with a death rate of 8 per 1000 children
during the study period as compared to intervention children where no
death was recorded. CONCLUSION: It is concluded that mass
supplementation of vitamin A led to significant reduction in
xerophthalmia and decline in mortality in the intervention area as
compared to control area.
Role of
vitamin A supplementation in the treatment of tuberculosis.Natl
Med J India. 2007 Jan-Feb;20(1):16-21.
Vitamin A
deficiency has been commonly observed in patients with tuberculosis.
Low serum retinol levels return to normal after antituberculosis
treatment even when no supplements are provided. The deficiency of
vitamin A observed in patients with tuberculosis might have
contributed to the development of tuberculous disease in them.
Alternatively, deficiency could be the result of loss of appetite,
poor intestinal absorption, increased urinary loss of vitamin A or
acute phase reaction in TB. Vitamin A deficiency lowers immunity while
vitamin A supplementation reduces morbidity and mortality,
particularly from measles and diarrhoea. Vitamin A supplementation
also decreases the mortality rate in HIV-infected children and delays
the progression of HIV disease in infected subjects. A higher
incidence of lung cancer and increased mortality have been observed in
smokers after beta-carotene supplementation. Zinc deficiency is also
common in tuberculosis, which may impose a secondary vitamin A
deficiency. Clinical trials have shown conflicting results regarding
the effect of supplementation of vitamin A, alone or with other
micronutrients, on time taken to sputum conversion in patients with
pulmonary tuberculosis. Supplementation with multiple micronutrients
(including zinc) rather than vitamin A alone may be more beneficial in
patients with tuberculosis, but clinical trials on such a combination
are lacking.
Benefit of
vitamin A supplementation on ascaris reinfection is less evident in
stunted children.J
Nutr. 2007 Jun;137(6):1455-9.
Despite the
common coexistence of vitamin A deficiency and Ascaris infection in
preschool children in developing countries, and despite the widespread
use of vitamin A supplements, remarkably little is understood about
the impact of vitamin A supplementation on this gastrointestinal
nematode. The Ministry of Health of Panama recently initiated a
vitamin A supplementation program in rural indigenous populations. We
took advantage of this initiative to assess the benefit of 200,000 IU
(60 mg retinol) vitamin A on reinfection with Ascaris following
deworming. Baseline stool exams, anthropometry, and socio-economic
data were collected for 328 preschool children from 12-60 mo of age
(106 supplemented within previous 3 mo and 222 unsupplemented within
previous 6 mo). All children were dewormed with albendazole, and
reinfection levels were monitored 3 and 5 mo later. Baseline
prevalence of Ascaris was 79.5%. Stepwise regression showed that
Ascaris intensity was lower in Vit A-supplemented children at baseline
and 3 mo after deworming, but not after 5 mo. As 61% of the children
were stunted, the impact of supplementation on Ascaris reinfection was
examined separately for stunted and children of normal height.
Prevalence and intensity of Ascaris at baseline and 3 mo after
deworming were lower in children of normal height, but in stunted
children the benefit was restricted to those who were dewormed within
6 wk of supplementation. Our study provides evidence that combined
vitamin A supplementation and deworming reduces Ascaris reinfection in
children living in areas of chronic parasitosis, but that the duration
of the benefit is less in stunted children.
Assessment of
vitamin A nutritional status in newborn preterm infants.Nutrition.
2007 Jun;23(6):454-60. Epub 2007 May 17.
OBJECTIVE: This study assessed the vitamin A nutritional status of
preterm infants determined by the vitamin A relative dose-response
test (RDR) compared with serum levels of vitamin A, retinol-binding
protein (RBP), transthyretin (TTR), and retinol relations with carrier
proteins. METHODS: Serum levels of retinol, RBP, and TTR and retinol/RBP,
retinol/TTR, and RBP/TTR molar ratios were determined in 120 infants
at 7 d and in 92 at 28 d. For the determination of the performance of
the tests, the RDR was considered the reference method. The
sensitivity and specificity for all possible cutoff values were
determined by constructing receiver operator characteristic curves.
The areas under the curves were used to estimate the overall accuracy
of the tests. The best cutoff values to be used for the calculation of
sensitivity and specificity were determined with 95% confidence
intervals. RESULTS: RDR indicated vitamin A deficiency in 60% of the
infants at 7 d and in 51.1% at 28 d. In the receiver operator
characteristic curves, the best area under the curve was 0.710
obtained for serum retinol at 28 d of postnatal age and considered
moderately accurate. The least inadequate cutoff level was set at 25
mg/dL, but no value was considered adequate due to low sensitivity
and/or low specificity. CONCLUSION: Compared with RDR, the
determination of serum levels of retinol, RBP, and TTR and their molar
ratios are not adequate to assess nutritional vitamin A status in
preterm infants.
Biochemical
assessment of vitamin A in schoolchildren from a rural community.J
Pediatr (Rio J). 2007
May/June;83(3):247-252.
OBJECTIVE: To
investigate the prevalence of vitamin A deficiency among
schoolchildren from a rural area in the Distrito Federal, Brazil, and
to correlate this with rates of anemia and malnutrition. METHODS: From
a total of 179 students, the study recruited 155 schoolchildren (5 to
18 years), whose parents gave permission for blood tests. Plasma
retinol concentration was assayed by high resolution liquid
chromatography, and levels of plasma vitamin A lower than 20 microg/dL
were defined as abnormal or deficient in vitamin A. Hemoglobin was
measured by an automated cell counter, and anemia was defined as serum
concentrations of less than 11.5 and 12.0 g/dL for children and
adolescents, respectively. Nutritional status was assessed using z
scores for weight/height, height/age and body mass index percentiles.
RESULTS: The results indicated that 33.55% of the schoolchildren
tested had a vitamin A deficiency, with a prevalence of 35.44% among
children (5-9 years) and 31.58% among adolescents (10-18 years). No
correlation was observed between the prevalence of vitamin A
deficiency and prevalence rates of anemia or malnutrition. Both sexes
and all ages were homogeneous for vitamin A deficiency. CONCLUSIONS:
The elevated prevalence of vitamin A deficiency among the children and
adolescents attending this rural school identify a public health
problem in the region. These results indicate that age groups from 5
years onwards should be included in those at risk of hypovitaminosis A
and that they should be included in public policies aimed at combating
hypovitaminosis A.
Vitamin A
deficiency (VAD), teratogenic, and surgical models of congenital
diaphragmatic hernia (CDH).Am
J Med Genet C Semin Med Genet. 2007 May
15;145(2):139-57.
Congenital
diaphragmatic hernia (CDH) is a congenital malformation that occurs
with a frequency of 0.08 to 0.45 per 1,000 births. Children with CDH
are born with the abdominal contents herniated through the diaphragm
and exhibit an associated pulmonary hypoplasia which is frequently
accompanied by severe morbidity and mortality. Although the etiology
of CDH is largely unknown, considerable progress has been made in
understanding its molecular mechanisms through the usage of genetic,
teratogenic, and surgical models. The following review focuses on the
teratogenic and surgical models of CDH and the possible molecular
mechanisms of nitrofen (a diphenyl ether, formerly used as an
herbicide) in both induction of CDH and pulmonary hypoplasia. In
addition, the mechanisms of other compounds including several
anti-inflammatory agents that have been linked to CDH will be
discussed. Furthermore, this review will also explore the importance
of vitamin A in lung and diaphragm development and the possible
mechanisms of teratogen interference in vitamin A homeostasis.
Continued exploration of these models will bring forth a clearer
understanding of CDH and its molecular underpinnings, which will
ultimately facilitate development of therapeutic strategies.
Vitamin A
stability in salt triple fortified with iodine, iron, and vitamin A.Food
Nutr Bull. 2006 Sep;27(3):252-9.
BACKGROUND:
Dietary micronutrient deficiencies, which lead to diseases such as
iodine deficiency disorders, iron-deficiency anemia, and vitamin A
deficiency, are serious public health problems in the developing
world. Fortifying salt with iodine, iron, and vitamin A is an
attractive approach to simultaneously reduce the deficiencies of these
three micronutrients in the diet. OBJECTIVE: To explore the technical
feasibility of producing triple-fortified salt fortified with iodine,
iron, and vitamin A that would be stable under the climatic conditions
of developing countries (i.e., high temperature and high humidity).
METHODS: Triple-fortified salt was obtained by granulation and
encapsulation of commercially produced vitamin A products, iodine, and
iron compounds. Vitamin A retention was determined in the presence of
five iron and two iodine compounds, in different combinations, under
three different storage conditions. The influence of commercial
stabilization techniques for the vitamin A palmitate source used
(spray-dried or dissolved in oil), and the type of binder used for
granulation on vitamin A retention in triple-fortified salt was
studied. The influence of temperature, humidity, and chemical
interactions on vitamin A stability in triple-fortified salt was also
investigated. RESULTS: The most stable formulation retained 77.73% of
vitamin A after 2 months of storage at 40 degrees C, 60% relative
humidity, and 95% under ambient conditions. CONCLUSIONS: The results
indicate that the production of a stable triple-fortified salt is
technically feasible.
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