Low Serum Retinol Concentrations Research Articles

Inadequate Niacin Intake Disrupts Growth and Retinol Homeostasis Resulting in Higher Liver and Lower Serum Retinol Concentrations in Male Rats

BackgroundNiacin-derived nicotinamide adenine dinucleotide is an essential cofactor for many dehydrogenase enzymes involved in vitamin A (VA) metabolism. Several countries with high prevalence of VA deficiency rely on maize, a poor source of available niacin, as a dietary staple. ObjectivesThis study evaluated the interaction of dietary niacin on VA homeostasis using male Sprague-Dawley rats, aged 21 d (baseline body weight 88.3 ± 6.6 g). MethodsAfter 1 wk of acclimation, baseline samples were collected (n = 4). Remaining rats (n = 54) were split into 9 groups to receive low tryptophan, VA-deficient feed with 3 different amounts of niacin (0, 15, or 30 mg/kg) and 3 different oral VA doses (50, 350, or 3500 nmol/d) in a 3 × 3 design. After 4 wk, the study was terminated. Serum, livers, and small intestine were analyzed for retinoids using high-performance liquid chromatography. Niacin and metabolites were evaluated with nuclear magnetic resonance. Plasma pyridoxal-P (PLP) was measured with high-performance liquid chromatography. ResultsNiacin intake correlated with serum retinol concentrations (r = 0.853, P < 0.001). For rats receiving the highest VA dose, liver retinol concentrations were lower in the 30-mg/kg niacin group (5.39 ± 0.27 μmol/g) than those in the 0-mg/kg and 15-mg/kg groups (9.18 ± 0.62 and 8.75 ± 0.07 μmol/g, respectively; P ≤ 0.05 for both). This phenomenon also occurred in the lower VA doses (P ≤ 0.05 for all). Growth and tissue weight at endline were associated with niacin intake (P ≤ 0.001 for all). Plasma PLP correlated with estimated niacin intake (r = 0.814, P < 0.001). ConclusionsOptimal niacin intake is associated with lower liver VA and higher serum retinol and plasma PLP concentrations. The extent to which vitamin B intake affects VA homeostasis requires further investigation to determine if the effects are maintained in humans.

Visceral and body adiposity are negatively associated with vitamin A nutritional status independently of Body Mass Index and recommended intake of vitamin A in Brazilian Women

Vitamin A (VA) has a negative association with body mass index (BMI) since it is involved in the regulation of body adiposity via nuclear receptors. However, few studies have investigated the relationship between VA nutritional status and the way body adipose is stored, which is the aim of this cross-sectional analytical study with Brazilian adult women in different BMI classes with the intake of VA recommended. VA nutritional status was assessed by serum retinol and β-carotene measurements, dietary intake, and diagnosis of night blindness (NB). Results: 268 women with mean age of 38.00±5.80 years. According to the BMI, 30.97% were normal weight, 14.18% overweight, 25.37% class I obesity, 14.55% class II, and 14.93% class III.The prevalence of low serum of β-carotene, retinol, and presence of NB in the total sample was 73.5%, 45.9%, and 20.1%, respectively. A total of 86.7% of normal weight women had inadequate visceral adiposity index (VAI) and 41.0% had inadequate body adiposity index (BAI).VAI was the body adiposity marker with the highest association with low serum retinol and b-carotene concentrations (P<.001). There was presence of NB in 100% of cases of inadequacy of BAI (P<.001). High visceral and body adiposity were associated with compromised VA nutritional status regardless of BMI and the recommended intake of VA. Additional measures to assess body adiposity, and especially its distribution, may collaborate in clinical practice to identify women at risk of compromising their VA nutritional status even when they are classified as normal weight according to their BMI.

Association of serum retinol concentration with normal-tension glaucoma.

To evaluate the association between serum retinol concentration and normal-tension glaucoma (NTG). A total of 345 study subjects were recruited in a prospective cross-sectional study: 101 patients with NTG, 106 patients with high-pressure primary open-angle glaucoma (POAG) and 138 healthy control subjects. Serum retinol concentration in fasting blood samples was determined by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). All study subjects were given complete ophthalmic examinations and diagnosed by two glaucoma sub-specialists. Serum retinol concentrations in NTG, POAG, and controls were 338.90 ± 103.23 ng/mL, 405.22 ± 114.12 ng/mL, and 408.84 ± 122.36 ng/mL respectively. NTG patients had lower serum retinol concentrations than POAG (p < 0.001) or healthy controls (p < 0.001). There was no statistical difference between the POAG and healthy controls (p = 0.780). Higher proportion of NTG patients (37.6%) than POAG (17.9%) or controls (21.7%) had serum retinol concentrations lower than 300 ng/mL. Serum retinol was positively correlated with optic nerve sheath diameter (ONSD) (r = 0.349, p = 0.001) in glaucoma patients and not associated with any other demographic features or ophthalmic biometric parameters in the NTG patients. Multivariate logistic regression showed that serum retinol (OR = 0.898, 95CI%: 0.851-0.947) was associated with incident NTG. NTG patients had lower serum retinol concentrations. Serum retinol uniquely associated with NTG makes it a new potential option for the diagnosis and treatment of the disease.

Serum retinol, β-carotene, and α-tocopherol as biomarkers for disease risk and milk production in periparturient dairy cows

The effectiveness of using serum vitamin concentrations as biomarkers to predict diseases in dairy cows during the periparturient period is not well known. The objective of this study was to evaluate the association between serum β-carotene, retinol, and α-tocopherol concentrations and periparturient cow diseases in commercial dairies. We measured serum concentrations of these vitamin-active compounds at dry-off and during close-up (approximately 3 wk before calving) and early lactation (approximately 7 d post-calving), and we examined their association with clinical diseases in the first 30 d in milk. Diseases were diagnosed by trained personnel and recorded using database software. Blood samples were taken from 353 cows from 5 different farms over a 3-yr period. Blood samples were analyzed for β-carotene, retinol, α-tocopherol, and cholesterol. We built separate mixed logistic regression models for each disease outcome: hyperketonuria, lameness, mastitis, uterine diseases (retained placenta or metritis), and an aggregate outcome. For the aggregate outcome, a cow was considered positive if she had one or more of the following: hyperketonuria, lameness, mastitis, uterine disease, pneumonia, milk fever, or displaced abomasum. Concentrations of all 3 fat-soluble vitamins decreased significantly in early lactation relative to the 2 prepartum sampling times. Serum retinol concentrations at close-up and early lactation were negatively associated with odds of developing postpartum hyperketonuria. At early lactation, cows with uterine disease had lower serum retinol concentrations than cows without uterine disease. Similarly, lower serum retinol concentrations were associated with greater odds of having any one disease in the aggregate outcome. First-test 305-d mature-equivalent milk yield was positively correlated with increased serum α-tocopherol and negatively correlated with β-carotene concentrations. This study demonstrates the potential for serum β-carotene, retinol, and α-tocopherol to serve as biomarkers for disease risk.

Burden of disease attributable to vitamin A deficiency in Iranian population aged less than five years: findings from the global burden of disease study 2010

BackgroundVitamin A deficiency (VAD) is considered as one of the most serious public health concerns in developing countriesand the leading cause of mortality in under-five-year-old children.A large number of young children and pregnant women especially in low-income, non-industrialized communities are more susceptible to VAD. This study aims to report the burden of disease (BOD) attributable to VAD in Iranian population aged less than 5 years by using data of the Global Burden of Disease (GBD) study 2010.MethodsThe GBD 2010 study calculated the proportion of deaths, years of life lost (YLLs), and years lived with disability (YLDs) and disability-adjusted life years (DALYs) attributable to VAD by using the comparative risk assessment (CRA). VAD defined as low serum retinol concentrations (plasma retinol concentration < 0.70 umole/L) among children aged less than five. The VAD outcomes consisted of mortality due to diarrhea, measles, malaria, neglected infectious diseases, morbidity due to malaria (children < 5 years), low birth weight and other perinatal conditions. Uncertainty in the estimates is presented as 95% uncertainty interval (UI).ResultsIn 1990, there were 371 (95% UI: 166,665) DALYs due to VAD per 100,000 under five-year-old Iranian children in both sexes. The DALYs rate had a downward trend throughout the following years and reached to 76 (95% UI: 33–139)in 2010.The DALYs in children aged under 5 years was 378 (95% UI: 153–747) years for boys and 363 (95% UI: 148–692) years for girls in 1990 which fell to 79 (95% UI: 32–149) and 73 (95% UI: 29–138) in boys and girls in 2010, respectively. The rates of YLDs attributable to VAD changed in both sexes from 87(95% UI: 34–162) in 1990 to 46 (95% UI: 17–69) in 2010. The highest rate of YLDs attributed to VAD was observed in children aged 1–4. On the other hand, the YLLs were mostly in the 0–1-year-oldchildren in all years except 2010.ConclusionIt was found that DALYs attributable to VAD in 1990, followed by a considerable reduction rate after a period of two decades, in 2010. Additional studies on the burden of diseases particularly at sub-national level with more accurate data are recommended.

Low Serum Retinol Concentration Explain Higher Hepcidin Levels In Mexican Older Adults

BackgroundElevated hepcidin levels have been linked to anemia of inflammation (AI). Retinol deficiency has shown to modulate hepcidin expression in animals; however, no studies have explored low serum retinol (LSR) concentration in older adults (OA) and their possible association with hepcidin concentrations. Anemia affect 27% of Mexican OA and inflammation may play a role in the production of anemia in this population. Understanding the mechanisms that play a role in the control hepcidin secretion is an important goal in the prevention of AI.AimTo explore if low serum retinol is associated with higher serum hepcidin concentrations in Mexican older adults (≥60years).MethodsMexican OA were participants in a crossectional study to identify the main causes of anemia. They were recruited in August 2015. Fasting serum samples were collected in 535 OA. Serum retinol (SR) was measured by HPLC and LSR was defined if SR&lt;20μg/dL. Hepcidin (ng/mL) was measured using a commercial ELISA kit. Due to skewed distribution of hepcidin, a quantil regression model was used to associate the LSR and hepcidin, adjusting by sex, age, BMI, ferritin, transferrin receptor, vitamin B12 status, IL‐6, C reactive protein, Alpha‐1‐acid glycoprotein, diabetes, hypertension, tertil of socioeconomic status, sarcopenia and functional disability.ResultsMean age was 71.5y for male and 70.7y for female. LSR was present in 3.2% of OA. Mexican OA with low serum retinol had 12.2 ng/mL higher hepcidin levels than OA with normal serum retinol levels (p=0.03). Hepcidin adjusted median (by confounders) were (median±EE): 19.4± 1.0 ng/mL in OA with normal serum retinol and 31.9±5.7 ng/mL in OA with LSR. Sarcopenic OA had higher hepcidin levels (coef: 7.5 ng/mL, p=0.03) than OA non‐sarcopenic.ConclusionsLSR levels in OA explain their higher hepcidin concentrations. Retinol concentrations affects iron homeostasis but the mechanism is unclear. This data document for the first time that in humans, low serum retinol concentration is inversely associated with hepcidin concentrations. Further longitudinal studies are needed to understand the role of serum hepcidin and Retinol in the development of AI in OA.Support or Funding InformationCONACYT‐FONSEC SSA/IMSS/ISSSTE SALUD 2014‐1, S0008‐2014‐1‐000000000234157

Albendazole increases serum retinol concentration in primary schoolchildren with low serum retinol

Background&lt;br /&gt;Soil-transmitted helminth (STH) infection is still a health problem in Indonesia. Vitamin A deficiency (VAD) is often found together with STH. The effect of the deworming program on the vitamin A status of primary school children is unknown. The objective of this study was to evaluate the effect of albendazole on serum retinol concentrations in primary school children.&lt;br /&gt;&lt;br /&gt;Methods&lt;br /&gt;An experimental study of pre-post test design without control was carried out on 118 children from grades 3-5 at one primary school in North Jakarta, from July to September 2014. Flotac examination was used to determine STH infections and high performance liquid chromatography was performed to measure serum retinol concentration. Stool and blood samples were taken twice: before and three weeks after treatment with albendazole 400 mg single dose for three consecutive days given to all children either infected or uninfected. Paired t-test was used to analyze the data. &lt;br /&gt;&lt;br /&gt;Results&lt;br /&gt;Of the 118 children, the prevalence of STH was 71.2%. The prevalence of low retinol serum (&amp;lt;1.05 mmol/L) was 17 (17.2%) and of mild VAD was 2 (2.0%). Albendazole given in 3 consecutive days could not increase serum retinol concentrations (p=0.055). Serum retinol concentration significantly increased after albendazole treatment in children with low retinol serum at baseline (p=0.001). &lt;br /&gt;&lt;br /&gt;Conclusions&lt;br /&gt;In children with low serum retinol concentration, treatment with albendazole increased retinol concentration. Integrated deworming and vitamin A supplementation strategies should be evaluated in this population.

High prevalence of vitamin A deficiency in Crohn's disease patients according to serum retinol levels and the relative dose-response test.

To assess the vitamin A status of patients with Crohn's disease (CD) by evaluating serum retinol levels and the relative dose response (RDR) test (liver retinol stores). Vitamin A nutritional status was measured by serum retinol obtained by high performance liquid chromatography and the RDR test for evaluation of the hepatic stores. Body composition was performed by densitometry by dual-energy X-ray absorptiometry. Vitamin A dietary intake was assessed from a semi-quantitative food frequency questionnaire. This study included 38 CD patients and 33 controls. Low serum retinol concentrations were detected in 29% of CD patients vs 15% in controls (P < 0.005). The RDR test was positive in 37% of CD patients vs 12% in controls, which indicated inadequate hepatic vitamin A stores (P < 0.005). Individuals with hypovitaminosis A had lower BMI and body fat compared with those without this deficiency. There was no association between vitamin A deficiency and its dietary intake, ileal location, presence of disease activity and prior bowel resections. Patients with CD have higher prevalence of vitamin A deficiency, as assessed by two independent methods.

Serum retinol concentrations in mothers and newborns at delivery in a public maternity hospital in Recife, northeast Brazil.

Serum retinol concentrations were compared in a consecutive series of 65 mother-newborn pairs at delivery in a public maternity hospital in Recife, Brazil, from January to August 2008 and examined their association with biological, socioeconomic, environmental and obstetrical characteristics. Serum retinol concentrations of the newborns (umbilical cord) and mothers (brachial venipuncture) were analyzed by high-performance liquid chromatography. Prevalence of low (< 0.70 micromol/L) and inadequate (< 1.05 micromol/L) serum retinol concentrations were observed in 23.1% (95% CI 13.9-35.5) and 23.0% (95% CI 13.5-35.8) among newborns and mothers respectively. The serum retinol distribution was lower in male than female infants (-0.4 micromol/L, p = 0.01) and, across both sexes, concentrations in paired newborn and mother were correlated (r = 0.27, p = 0.04). Further, maternal status explains only 7% of the variance in retinol concentrations in newborn's cord plasma. Among mothers delivering in public facilities in Recife, hypovitaminosis may exist.

Malaria and vitamin A deficiency in African children: a vicious circle?

Vitamin A deficiency and malaria are both highly prevalent health problems in Africa. Vitamin A deficiency affects over 30 million children, most of whom are in the age-group (under five years) most affected by malaria. Vitamin A deficiency increases all-cause mortality in this part of the population, and malaria is an important cause of death in children at this age. A low serum retinol concentration (a marker of vitamin A deficiency) is commonly found in children suffering from malaria, but it is not certain whether this represents pre-existing vitamin A deficiency, a contribution of malaria to vitamin A deficiency, or merely an acute effect of malaria on retinol metabolism or binding. In this paper, available evidence in support of a causal relationship in each direction between vitamin A deficiency and malaria is reviewed. If such a relationship exists, and especially if this is bidirectional, interventions against either disease may convey an amplified benefit for health.

Serum Retinol, α-tocopherol, and Lipid Peroxide Concentrations in Low-income Indian Pregnant Mothers

Serum alpha-tocopherol, retinol, and malondialdehyde concentrations were measured at 7(th) month of pregnancy in 122 women from low socio-economic background. Maternal anthropometric measurements, 24-hour nutrient intakes, and pregnancy outcome were recorded. One-third (34.3 %) of mothers had low birth weight babies and 10 % delivered preterm. Maternal diets were inadequate in all the nutrients, the most limiting being vitamin A. Three-fourths of mothers had intakes less than 25 % of the Indian recommended daily intake (RDI) of 600 microg retinol equivalents/day. Serum alpha-tocopherol concentrations of 98 % were indicative of deficiency and almost half the mothers had low serum retinol concentrations (< or =10 microg/dL). Mean malondialdehyde level was 7.0 +/- 1.4 nmoles/mL. These values are higher than reports in the literature and were attributable to poor intake of most dietary antioxidants. Malondialdehyde concentrations were negatively correlated with serum alpha-tocopherol. Birth weight was positively correlated with maternal weight and biceps skinfold thickness, macronutrient intakes, serum retinol, and alpha-tocopherol concentrations. Preterm delivery was associated with low anthropometric measurements and low nutrient intakes especially vitamin A. Mothers who delivered preterm had significantly lower malondialdehyde concentrations than those who delivered at term. The role of antioxidant nutrients, especially vitamin A and oxidative stress in relation to fetal growth and pregnancy outcome among mothers from low socioeconomic settings requires attention.

Serum Retinol Concentrations in Hospitalized Severe Protein-energy Malnourished Children

Vitamin A deficiency (VAD) is a major nutritional problem in many developing countries. Vitamin A status has been reported to be adversely affected in protein-energy malnutrition (PEM). To assess and compare serum retinol concentrations in hospitalized children with severe PEM and normal ones. A prospective series of 34 malnourished and 29 normal control children, <60 months old, hospitalized at IMIP, Recife-PE were recruited for the study between August 2004 and May 2005. Serum retinol level was assayed by high performance liquid chromatography and concentrations adjusted for presence of inflammation as evidenced by levels of C-reactive protein. Blood retinol level was compared according to nutritional status (severe PEM versus normal), gender, age, maternal schooling, family income, breastfeeding practice, residence and perceived morbidity. The prevalence of low serum retinol (<0.70 micromol l(-1)) was 41.2% in children with severe PEM and 24.1% in normal children. Serum retinol concentrations were lower in children whose mothers had low schooling (p = 0.025) and families with low per capita income (p = 0.049), regardless of their nutritional status. Serum retinol concentrations had similar distribution between children with severe PEM and normal, when adjusted for gender (p > 0.05), age (p > 0.05), maternal schooling (p > 0.05), family income (p > 0.05), breastfeeding practice (p > 0.05) and residence (p > 0.05). However, malnourished children with diarrhoea showed lower serum retinol concentrations (p = 0.021) compared to those without diarrhoea. VAD was prevalent in hospitalized children with severe PEM and also among normal ones although in lesser magnitude. Intervention for prevention and control of deficiency of vitamin A are recommended in settings where diarrhea is endemic and there are unfavorable socio-economical conditions.

A Multiple-Micronutrient-Fortified Beverage Affects Hemoglobin, Iron, and Vitamin A Status and Growth in Adolescent Girls in Rural Bangladesh ,

Adolescent girls have high nutrient needs and are susceptible to micronutrient deficiencies. The objective of this study was to test the effect of a multiple-micronutrient-fortified beverage on hemoglobin (Hb) concentrations, micronutrient status, and growth among adolescent girls in rural Bangladesh. A total of 1125 girls (Hb ≥70 g/L) enrolled in a randomized, double-blind, placebo-controlled trial and were allocated to either a fortified or nonfortified beverage of similar taste and appearance. The beverage was provided at schools 6 d/wk for 12 mo. Concentrations of Hb and serum ferritin (sFt), retinol, zinc, and C-reactive protein were measured in venous blood samples at baseline, 6 mo, and 12 mo. In addition, weight, height, and mid-upper arm circumference (MUAC) measurements were taken. The fortified beverage increased the Hb and sFt and retinol concentrations at 6 mo (P < 0.01). Adolescent girls in the nonfortified beverage group were more likely to suffer from anemia (Hb <120 g/L), iron deficiency (sFt <12 μg/L), and low serum retinol concentrations (serum retinol <0.70 μmol/L) (OR = 2.04, 5.38, and 5.47, respectively; P < 0.01). The fortified beverage group had greater increases in weight, MUAC, and BMI over 6 mo (P < 0.01). Consuming the beverage for an additional 6 mo did not further improve the Hb concentration, but the sFt level continued to increase (P = 0.01). The use of multiple-micronutrient-fortified beverage can contribute to the reduction of anemia and improvement of micronutrient status and growth in adolescent girls in rural Bangladesh.

Acute-phase protein levels, diarrhoea, Trichuris trichiura and maternal education are predictors of serum retinol: a cross-sectional study of children in a Dhaka slum, Bangladesh.

The objectives of the present study were to identify predictors of serum retinol concentration as well as to assess the prevalence of low serum retinol concentration, in both the whole population after correcting for the effect of serum C-reactive protein (CRP) (using multiple categories), and the healthy subgroup. A cross-sectional study of 579 apparently healthy children, aged 3-7 years from a Dhaka slum, Bangladesh, was conducted. The effects of age, gender, serum CRP and alpha1-antichymotrypsin, reported morbidity (during the previous 2 weeks), Ascaris lumbricoides and Trichuris trichiura infections, parental education, wasting, stunting and underweight on serum retinol were estimated using multiple linear regression. The mean serum retinol concentration was 0.84 (sd 0.27) micromol/l. Elevated serum CRP levels, reported diarrhoea, reported nasal discharge and T. trichiura infection were negative predictors of serum retinol, whereas maternal education was a positive predictor. Compared with a serum CRP level of < 1 mg/l, CRP levels of 2 to < 5, 5 to < 10 and > or = 10 mg/l were associated with 0.12, 0.16 and 0.32 micromol/l lower serum retinol, respectively. The prevalence of low serum retinol (< 0.70 micromol/l) fell from 31.2 % to 15.6 % in the whole population, after correcting for the effect of CRP, and was 20.1 % in the healthy subgroup (CRP < 2 mg/l). The prevalence of low serum retinol was high but overestimated due to the effect of CRP. Interventions are needed to address low serum retinol in Bangladesh. Controlling diarrhoea, nasal discharge and T. trichiura infection and improving maternal education may be important interventions. The use of multiple categories of acute-phase proteins and cut-off values that indicate elevated levels need further research.

Distribution of Anemia Associated with Micronutrient Deficiencies Other than Iron in a Probabilistic Sample of Mexican Children

Background: This investigation aims to explore the association among anemia and vitamins A, C, and folate deficiencies in a probabilistic sample of Mexican children. Methods: Data on hemoglobin, serum vitamins A and C and folate concentrations and percent transferrin saturation (PTS) in children 0.5–11 years (n = 1,770) were extracted from the database of the probabilistic Mexican National Nutrition Survey 1999 (NNS-99). Results: Overall, 16.6% of children were anemic. Iron deficiency children with or without anemia had more frequent low serum retinol (40.6 vs. 16% and 27.7 vs. 11.9%, p < 0.05, respectively) and lower hemoglobin folate (11.5 vs. 22%, p < 0.05) than their non-iron deficiency counterparts. Mean concentrations of serum iron (p < 0.01), folate (p < 0.001) and retinol (p < 0.0001), but not ascorbic acid (p < 0.6), were significantly lower in anemic than in nonanemic children. In a linear regression model, 15% of hemoglobin variation in children was explained by retinol, folate and PTS, but not vitamin C (p <0.0001). Conclusion: Anemia was mostly associated with iron deficiency and with a lesser proportion of folate and vitamin A deficiencies. Vitamin A deficiency might be overestimated since iron deficiency may lower serum retinol concentrations. Interventions aimed to reduce anemia in this population must consider interactions between those micronutrients in designing strategies.

Serum retinol is associated with hemoglobin concentration in infants who are not vitamin A deficient

There is evidence that vitamin A benefits hematopoiesis and iron metabolism. For this reason, we investigated the relationship of serum retinol concentration to hemoglobin concentration and biochemical indicators of iron status in Canadian aboriginal infants. No infant had biochemical evidence for vitamin A deficiency (serum retinol <0.35 μmol/L) although 25.6% had anemia (hemoglobin <110 g/L) and 20.4% had iron deficiency (serum ferritin <10 μg/L). Serum retinol concentration was significantly correlated with hemoglobin concentration (r = 0.30, p < 0.001, n = 185) and serum iron concentration (r = 0.44, p < 0.001, n = 166) but not with serum ferritin concentration. Anemic infants had lower serum retinol concentrations than those without anemia (1.09 ± 0.33 μmol/L vs. 1.36 ± 0.36 μmol/L, p < 0.01). Infants given vitamin supplements that contained vitamin A, ascorbic acid, and vitamin D 3 had a higher hemoglobin concentration than infants not given supplements (117 ± 11 vs. 113 ± 10 g/L, p = 0.04) and a lower prevalence of anemia (21.9% vs. 37.0%, p = 0.05). In conclusion, vitamin A was positively associated with hemoglobin concentration in this pediatric population of infants, many of whom had anemia and iron deficiency.

Randomized efficacy trial of a micronutrient-fortified beverage in primary school children in Tanzania

Dietary supplements providing physiologic amounts of several micronutrients simultaneously have not been thoroughly tested for combating micronutrient deficiencies. We determined whether a beverage fortified with 10 micronutrients at physiologic doses influenced the iron and vitamin A status and growth of rural children (aged 6-11 y) attending primary schools. In this randomized, double-blind, placebo-controlled efficacy trial, children were assigned to receive the fortified beverage or an unfortified beverage at school for 6 mo. There were nonsignificant differences at baseline between children in the fortified and nonfortified groups in iron status, serum retinol, and anthropometry. At the 6-mo follow-up, among children with anemia (hemoglobin < 110 g/L), there was a significantly larger increase in hemoglobin concentration in the fortified group than in the nonfortified group (9.2 and 0.2 g/L, respectively). Of those who were anemic at baseline, 69.4% in the nonfortified group and 55.1% in the fortified group remained anemic at follow-up (RR: 0.79), a cure rate of 21%. The prevalence of children with low serum retinol concentrations (< 200 microg/L) dropped significantly from 21.4% to 11.3% in the fortified group compared with a nonsignificant change (20.6% to 19.7%) in the nonfortified group. At follow-up, mean incremental changes in weight (1.79 compared with 1.24 kg), height (3.2 compared with 2.6 cm), and BMI (0.88 compared with 0.53) were significantly higher in the fortified group than in the nonfortified group. The fortified beverage significantly improved hematologic and anthropometric measurements and significantly lowered the overall prevalence of anemia and vitamin A deficiency.

Estado nutricional y malaria en escolares de la comunidad de Santo Tomás en Iquitos, Perú

A 9 month follow-up pilot study was performed in a 52-schoolchildren cohort at Santo Tomas in Iquitos, Peru. Their nutritional status was determined at the beginning and at the end of the study, as well as the presence of malaria. 9,6% children were underweight according to their age, 32,7% were smaller than what was expected for their age, 61,9% had low serum retinol concentrations and 7,7 had a body mass index (BMI) below the 5 th percentile. The parameters measured did not have significant variations when comparing initial and final measurements. The small height found was associated with the frequency of malaria (RR: 5,49, p= 0,032). This variable may be an indicator for deficient living conditions; which, in turn, favor malaria transmission.

Zinc supplementation as adjunct therapy in children with measles accompanied by pneumonia: a double-blind, randomized controlled trial

Zinc deficiency, common in developing countries, is associated with decreased immunocompetence. Zinc supplementation benefits children with acute and persistent diarrhea and prevents pneumonia. Most deaths from vaccine-preventable diseases are from measles and whooping cough; pneumonia is the most common complication of measles and often the proximate cause of related deaths. We evaluated the effect of zinc supplementation on episodes of illness in children with measles accompanied by pneumonia. In a double-blind, randomized controlled trial, children aged 9 mo-15 y who were admitted to the Infectious Diseases Hospital in Calcutta with clinically severe measles accompanied by pneumonia and who had been ill for </= 7 d were randomly assigned to receive zinc (20 mg, in elemental form as acetate, twice daily for 6 d) or a placebo. All patients received standard treatment with antibiotics and an initial 100 000-IU dose of vitamin A (as palmitate) by mouth. Time-to-event analysis using the Cox proportional hazards model (42 in the zinc group and 43 in the placebo group) showed that the time needed for the resolution of fever and tachypnea, the return of appetite, and the achievement of a "much improved" or "cured" status was not different between the 2 groups. A high proportion of children had low serum retinol and zinc concentrations. Improvement in serum zinc and retinol concentrations after 6 d of treatment was not different between the 2 groups. Children with severe measles accompanied by pneumonia treated with antibiotics and vitamin A did not show any additional benefit from also receiving a zinc supplement.

Biochemical Indicators of Vitamin A Deficiency: Serum Retinol and Serum Retinol Binding Protein

Two biochemical indicators are currently recommended for determining whether vitamin A deficiency (VAD) is a public health problem: serum retinol and serum retinol-binding protein (RBP). After consideration of 40 data sets and the original rationale for previously proposed cut-offs, a cut-off for serum retinol concentration was proposed at <0.70 micro mol/L (20 micro g/dL) in > or =15% of the sampled population. This cut-off should be applied to a representative group of preschool age children (6-71 mo). Because measurement of low serum retinol concentrations requires high precision, analysis should be done by HPLC. For serum RBP, a cut-off cannot be reliably specified, because available data are too few and too variable. However, because serum RBP concentration correlates well with serum retinol concentration, it can be used to determine whether VAD is a public health problem in those populations for which the relationship between serum concentrations of retinol and RBP have been established. More efforts to establish a reliable cut-off for RBP is warranted, because analysis, in particular radial immunodiffusion (RID), is relatively simple and inexpensive. Whereas HPLC and RID analyses must be done in a laboratory, methods are being developed for assessing serum retinol and RBP under more remote conditions.