Retinol binding protein as a surrogate measure for serum retinol: studies in vitamin A-deficient children from the Republic of the Marshall Islands

BACKGROUND: Serum retinol is transported by retinol binding protein (RBP), which has one high-affinity binding site for retinol; consequently, the molar ratio of retinol to RBP in the circulation is approximately 1 to 1. In vitamin A deficiency (VAD), both serum retinol and RBP decline. However, the retinol-RBP relation has not been well studied in populations with a high incidence of severe VAD. OBJECTIVE: The purpose of this study was to determine whether RBP is a good surrogate for serum retinol at the very low retinol concentrations encountered in VAD. DESIGN: The stoichiometric relation between retinol and RBP was studied in 239 Marshallese children: 65 with severe VAD (< or = 0.35 micromol retinol/L), 94 with moderate VAD (0.36-0.70 micromol retinol/L), and 80 with vitamin A sufficiency (> 0.70 micromol retinol/L). RESULTS: Excellent correlation between retinol and RBP (r = 0.94) was observed across all retinol concentrations. Severe VAD was predicted with 96% sensitivity and 91% specificity on the basis of an RBP cutoff of < or = 0.48 micromol/L, whereas moderate VAD was predicted with 87% sensitivity and 98% specificity on the basis of an RBP cutoff of < or = 0.70 micromol/L. CONCLUSIONS: The use of RBP results in the classification of essentially the same children with VAD as does retinol, and RBP is an excellent surrogate for serum retinol. Considering the relative ease of measuring RBP with immunodiagnostic kits compared with that of serum retinol by HPLC, the use of RBP concentrations to assess VAD may be particularly advantageous in field settings. Consequently, measuring RBP concentrations may be a practical alternative to measuring serum retinol in population surveys assessing the prevalence of VAD.     

Vitamin A inadequacy observed in a group of 2- to 6-year-old children living in Kwangju, Republic of Korea

Dietary intakes and plasma concentrations of retinol and carotenoids were estimated in assessing the vitamin A status of young children in Kwangju, Republic of Korea. Three consecutive 24-hour food recalls and fasting blood samples were obtained from 123 healthy children (58 boys, 65 girls), aged 2-6 years. The daily vitamin A intake (mean +/- SD) was 355.9 +/- 178.1 microg retinol equivalents or 239.0 +/- 111.2 microg retinol activity equivalents. Provitamin A carotenoid intakes were 1211.2 +/- 840.0 microg/day beta-carotene, 234.6 +/- 231.7 microg/day alpha-carotene, and 149.1 +/- 160.7 microg/day beta-cryptoxanthin. Approximately 15-26% of subjects consumed < Korean Estimated Average Requirements (EAR) for vitamin A; whereas, 57-64% consumed < EAR for vitamin A for USA/Canadians. The mean plasma retinol concentration was 1.108 +/- 0.244 micromol/L. There were no significant correlations between intakes and plasma concentrations of retinol and carotenoids. Only 2.4% of children were vitamin A-deficient based on having plasma retinol concentrations <0.70 micromol/L. Plasma retinol concentrations of 42.3% of subjects were 0.70 - <1.05 micromol/L, which is considered indicative of potentially suboptimal vitamin A status. Therefore, some children may be at risk of inadequate vitamin A status in Kwangju, Republic of Korea.     

Vitamin A deficiency in patients with diarrhea and HIV infection in Ethiopia

Diarrhea, micronutrient deficiencies and HIV/AIDS are major public health problems in developing countries, especially in sub-Saharan Africa. This study was aimed to investigate serum levels of vitamin A in diarrheic patients with and without HIV co-infection compared to healthy controls. Two hundred eleven diarrheic patients (110 HIV infected), 87 apparently healthy controls and 41 asymptomatic HIV seropositive blood donors who visited the University of Gondar Hospital, in Gondar, Ethiopia were included. Stool samples were examined for enteropathogens following the standard procedures. Serum vitamin A levels were measured by high performance liquid chromatography. Shigella species were isolated from 8.5% of the patients while intestinal parasites were detected in 32.2% without significant difference by HIV serostatus. The mean+/-SD serum vitamin A in diarrheic patients with (0.82+/-0.59 micromol/L) and without (0.84+/-0.54 micromol/L) HIV co-infection and in asymptomatic HIV infected blood donors (0.96+/-0.52 micromol/L) was significantly lower than that in healthy controls (1.52+/-0.71 micromol/L), p<0.001. Vitamin A deficiency (VAD, serum retinol < 0.70 micromol/L) was observed in 52.7% and 45.5% of diarrheic patients with and without HIV co-infection, respectively. About 13% of healthy controls and 29.3% of asymptomatic HIV infected blood donors were deficient in vitamin A. The levels of serum vitamin A were not associated with the presence of intestinal parasites or Shigella species. The findings demonstrate that VAD is a severe public health problem among diarrheic patients in Gondar, Ethiopia. Intervention programmes involving health and nutrition education and supplementation of vitamin A might help in reducing morbidity in such patients.     

Elevated vitamin A intake and serum retinol in preadolescent children with cystic fibrosis

BACKGROUND: Persons with cystic fibrosis (CF) and pancreatic insufficiency (PI) are at risk of vitamin A deficiency because of steatorrhea, despite pancreatic enzyme replacement. Long-standing vitamin A supplementation may increase the risk of vitamin A toxicity. OBJECTIVE: The aim was to describe the vitamin A intake and serum retinol concentrations of preadolescent children with CF, PI, and mild-to-moderate pulmonary disease, who were cared for under current practice recommendations. DESIGN: This cross-sectional study evaluated children aged 8.0-11.9 y with CF and PI from 13 US CF centers. Dietary and supplemental vitamin A intakes were compared with the Dietary Reference Intakes (DRIs) for healthy children, CF recommendations, and data from the National Health and Nutrition Examination Survey (NHANES), 1999-2000. Serum retinol concentrations were compared with NHANES data. RESULTS: The 73 subjects with CF had a dietary vitamin A intake of 816 +/- 336 microg retinol activity equivalents (165 +/- 69% of the recommended dietary allowance), which was similar to the NHANES value. The supplement intake provided 2234 +/- 1574 microg retinol activity equivalents/d and exceeded recommendations in 21% of the subjects with CF. Total preformed retinol intake exceeded the DRI tolerable upper intake level in 78% of the subjects with CF. The serum retinol concentration was 52 +/- 13 microg/dL (range: 26-98 microg/dL), which was significantly higher than the NHANES value (37 +/- 10 microg/dL; range: 17-63 microg/dL; P < 0.001). CONCLUSION: Although supplementation helps to prevent vitamin A deficiency in children with CF and PI, their high vitamin A intakes and serum retinol concentrations suggest that usual care may result in excessive vitamin A intake and possible toxicity that would increase the risk of CF-associated liver and bone complications.     

Dietary vitamin A intakes of Filipino elders with adequate or low liver vitamin A concentrations as assessed by the deuterated-retinol-dilution method: implications for dietary requirements

BACKGROUND: The vitamin A requirements of elderly humans have not been studied. OBJECTIVE: In a cross-sectional study of 60-88-y-old men (n = 31) and women (n = 31) in rural Philippines, we assessed the dietary intakes of elders with adequate (> or = 0.07 micromol/g) or low (< 0.07 micromol/g) liver vitamin A concentrations to estimate vitamin A requirements for this age group. DESIGN: Total-body vitamin A was assessed by the deuterated-retinol-dilution technique; liver vitamin A concentrations were assessed by assuming that liver weight is 2.4% of body weight and that, in this marginally nourished population, 70% of total-body vitamin A is in the liver; serum retinol was measured by HPLC; and dietary intakes were assessed with 3 nonconsecutive 24-h dietary recalls. The mean vitamin A intake + 2 SDs of subjects with adequate liver vitamin A concentrations was used to estimate an acceptable or sufficient vitamin A intake value for elders. RESULTS: The mean (+/- SD) vitamin A intakes of the men and women with adequate vitamin A in liver were 135 +/- 86 and 134 +/- 104 microg retinol activity equivalents (RAE)/d, respectively; intakes of the men and women with low vitamin A in liver were 75 +/- 53 and 60 +/- 27 microg RAE/d, respectively. Total-body vitamin A or liver vitamin A but not serum retinol correlated with dietary RAE, preformed vitamin A, beta-carotene, fat, and protein. An estimated acceptable or sufficient dietary vitamin A intake associated with adequate liver vitamin A concentrations in elders is 6.45 microg RAE/kg body wt; for a reference 76-kg man and a 61-kg woman, these values are approximately 500 and 400 microg RAE/d, respectively. CONCLUSION: The dietary vitamin A intakes of elders with adequate or low liver vitamin A concentrations as estimated by use of the deuterated-retinol-dilution technique are useful for assessing vitamin A requirements.     

Assessment of vitamin A status of preschool children in a sub-Saharan African setting: comparative advantage of modified relative-dose response test

A nationally-representative sample of 2,696 preschool children living in Congo was examined during Au gust-September 2003 to determine the rates of vitamin A deficiency. Ninety clusters of 30 children, aged six months to six years, were selected, using a randomized two-level cluster-sampling method. Vitamin A deficiency was determined by assessing the prevalence of active xerophthalmia (nightblindness and/or Bitot spots) in the cross-over sample of 2,696 individuals. A semi-quantitative seven-day dietary questionnaire was concurrently applied to the mothers of children enrolled to estimate the latter's consumption of vitamin A-rich food. Vitamin A status was assessed by performing the modified relative dose-response test (MRDR) on dried blood spots (DBS) from a subsample of 207 children aged less than six years and the impression cytology with transfer (ICT) test on a subsample of 1,162 children. Of the children enrolled, 5.2% suffered from nightblindness, 8.0% had Bitot spots, and 2.5% had other vitamin A deficiency sequellae. Fifty-three percent of the ICT tests showed the presence of vitamin A deficiency. The biochemical MRDR test showed that the vitamin A status of 30% of the study children was critical. Twenty-seven of them had retinol levels of < 10 microg/dL [mean +/- standard deviation (SD) 7.02 +/- 2.0 microg/dL], and 50% had retinol levels of 10-20 microg/dL (mean +/- SD 14.2 +/- 2.83 microg/dL). The poor health status and low rates of consumption of vitamin A-rich food are the main factors determining critical status. Vitamin A deficiency, reflecting poor nutrition and health, is a serious public-health issue among children aged less than six years in Congo.     

Vitamin A deficiency is prevalent in children less than 5 y of age in Nigeria

Vitamin A deficiency (VAD) is a serious and widespread public health problem in developing countries. We conducted a nationwide food consumption and nutrition survey in Nigeria to help fomulate strategies to address VAD, among other deficiencies. One objectives was to assess the vitamin A status of children <5 y old. A total of 6480 households with a mother and child <5 y old were randomly sampled. Blood samples were collected by venipuncture and processed to obtain serum for measurement of retinol concentration by HPLC. Nationwide, 29.5% of children <5 y old were vitamin A deficient (serum retinol <0.70 micromol/L). The proportions of children with VAD differed among the agroecological zones; incidences were 31.3% in the dry savanna, 24.0% in the moist savanna, and 29.9% in the humid forest (P < 0.001). More children (P < 0.05) with severe deficiency (serum retinol < 0.35 micromol/L) lived in the humid forest (7.1%) than in the dry (3.1%) or moist savanna (2.4%). The distribution of VA in children <5 y old was 25.6% in the rural sector, 32.6% in the medium, and 25.9% in the urban sector (P < 0.05). In conclusion, VAD is a severe public health problem in Nigeria. Although the proportion of children with low serum vitamin A levels varies agroecologically and across sectors, it is an important public health problem in all zones and sectors.     

Rapid and simple measurement of retinol in human dried whole blood spots

We describe an improved method for the measurement of retinol in dried blood spots (DBS) on filter paper. Retinol in human DBS on filter paper was analyzed by normal phase HPLC after a simple extraction method. Retinol associated with its binding protein was eluted from the paper into aqueous solution facilitated by ultrasonic agitation. Retinol associated with retinol binding protein was denatured with acetonitrile, and then retinol was isolated in a single hexane extract and analyzed directly by HPLC. When analyzing DBS, the individual plasma volume of the spots was calculated by measuring the sodium content or by weighing the blood spots. The described method yielded low intra- and interassay variability (<6%), with sufficient sensitivity (detection limit, 0.1 micromol/L) and good recovery (97% spike). Compared with matching plasma samples, DBS retinol consistently decreased 18-23% during the 1st wk of storage. After 1 wk, retinol remained stable in the blood spots at 23 degrees C for >3 mo. In conclusion, the analysis of retinol in DBS by HPLC is comparable to retinol analysis in serum. The variability of the method was reduced by using sodium concentration to estimate sample volume. Collection of DBS for retinol analysis is appropriate under field conditions, where it is difficult to centrifuge or freeze blood samples.     

Validation of a rapid enzyme immunoassay for the quantitation of retinol-binding protein to assess vitamin A status within populations

OBJECTIVE: To compare the prevalence of vitamin A deficiency (VAD) among Cambodian preschool children as determined by the retinol-binding protein-enzyme immunoassay (RBP-EIA) and direct measurement of serum retinol by high-performance liquid chromatography (HPLC). SETTING AND SUBJECTS: Sera from 359 children were randomly selected from archived specimens collected in a national VAD prevalence survey in Cambodia. METHODS: Sera were first analyzed for retinol content by HPLC and then subjected to analysis using RBP-EIA to determine serum RBP concentrations. National Institute of Standards and Technology and control sera were used to ensure quality and accuracy for each set of analyses. To classify VAD, the same cutoff point of <0.70 micromol/l was employed for each indicator. RESULTS: Overall, the prevalence of VAD based on serum retinol was 22.3% (95% confidence interval (CI): 18.0, 26.6), whereas the RBP-EIA indicated a VAD prevalence of 20.9% (95% CI: 16.7, 25.1). A simple linear regression model indicated an R2 of 0.79, and a receiver operating curve analysis revealed an area under the curve of 0.92. CONCLUSIONS: We found no significant difference between the results of RBP-EIA compared to retinol analyzed by HPLC in estimating the prevalence of VAD. Use of the test could enable public health authorities to assess the extent of VAD and track progress in control programs in resource-poor settings.     

Neighborhood Deprivation is associated with lower levels of serum carotenoids among adults participating in the Third National Health and Nutrition Examination Survey

OBJECTIVE: This study tested the hypothesis that neighborhood deprivation will be associated with lower levels of serum carotenoids in comparison with wealthy residential areas. DESIGN: Cross-sectional, nationally representative survey data were used to assess the relationship between neighborhood level socioeconomic status and serum carotenoids. SUBJECTS: Seventeen thousand two participants aged 17 years and older from the Third National Health and Nutrition Examination Survey were linked with 1990 census data. MAIN OUTCOME MEASURES: Serum levels of lycopene, beta-carotene, alpha-carotene, lutein/zeaxanthin, and beta-cryptoxanthin. STATISTICAL ANALYSIS: Multivariate linear regression was used to model the association of serum carotenoids and neighborhood deprivation, which is a summary index of 11 indicators for tract level socioeconomic status. Adjustments are made for individual level age, sex, years of education, household income, employment, race/ethnicity, body mass index, serum cotinine, alcohol use, physical activity, and serum cholesterol. RESULTS: Multivariate analysis revealed a negative and statistically significant association between high levels of neighborhood deprivation and beta-carotene (beta=-2.98 microg/dL [-0.06 micromol/L], P=0.00), alpha-carotene (beta=-1.28 microg/dL [-0.02 micromol/L], P=<0.0001), lutein/zeaxanthin (-1.69 microg/dL [-0.03 micromol/L], P=0.00, beta-cryptoxanthin (beta=-1.34 microg/dL [-0.02 micromol/L], P<0.0001), and total carotenoids (beta=-8.20 microg/dL, P=<0.0001). Lycopene was not related to neighborhood deprivation. Adjusted mean levels of carotenoids for high deprivation neighborhoods were lower than neighborhoods with low deprivation: beta-carotene=8.72 microg/dL [0.16 micromol/L] vs 20.64 microg/dL [0.38 micromol/L], alpha-carotene=0.44 microg/dL [0.008 micromol/L] vs 5.56 microg/dL [0.10 micromol/L], lutein/zeaxanthin=13.79 microg/dL [0.24 micromol/L] vs 20.55 microg/dL [0.36 micromol/L], beta-cryptoxanthin=4.57 microg/dL [0.08 micromol/L] vs 9.93 microg/dL [0.18 micromol/L], lycopene=22.07 microg/dL [0.41 micromol/L] vs 25.63 microg/dL [0.48 micromol/L], and total=49.56 microg/dL vs 82.36 microg/dL. CONCLUSIONS: Neighborhood deprivation was associated with lower serum levels of carotenoids. There was a substantial disparity between low deprivation and high deprivation residential areas with respect to fruit and vegetable intake.     

Vitamin A equivalence of spirulina beta-carotene in Chinese adults as assessed by using a stable-isotope reference method

BACKGROUND: Spirulina is a high-protein food supplement that contains carotenoids. OBJECTIVE: The objective of the study was to determine the vitamin A equivalence of spirulina beta-carotene in humans. DESIGN: Spirulina was grown in a 23 atom% (2)H(2)O cultural solution. Spirulina beta-carotene showed the greatest enrichment as [(2)H(10)]trans beta-carotene. Ten healthy Chinese men with a mean (+/-SD) serum retinol concentration of 1.7 +/- 0.3 micromol/L and a body mass index (in kg/m(2)) of 23 +/- 3 consumed 5.8 micromol [(13)C(10)]retinyl acetate in oil as a reference dose with a breakfast containing 13 g fat. One week later, each subject consumed 7.9 mumol trans beta-carotene in spirulina with a breakfast containing 22 g fat. All subjects followed diets low in carotenoid and vitamin A. Forty blood samples were collected from each subject over a span of 56 d. Concentrations and enrichments of retinol and beta-carotene in serum samples were determined by using HPLC and a mass spectrometer. RESULTS: Compared with the serum response to [(13)C(10)]retinyl acetate dose, the mean conversion factor of spirulina beta-carotene to retinol was 4.5 +/- 1.6 (range: 2.3-6.9) by weight. It was estimated that 80% of the conversion occurred within the first 24 h after spirulina administration. CONCLUSION: In a group of well-nourished, normal-weight Chinese men following low-vitamin A diets, 4.5 mg spirulina beta-carotene consumed with 22 g fat has the same vitamin A activity as does 1 mg retinyl acetate.     

Liver and kidney function tests amongst paint factory workers in Nkpor, Nigeria

Lead, cadmium, nickel and other industrial metals used as part of paint varnishes have been reported to have adverse health implications. An evaluation study on some toxicological effects of occupational exposure to paint, among 25 occupationally exposed artisans and 25 students (control) of Ichi Technical College, Ichi Ekwusigo Local Government Area, Anambra State, Nigeria was carried out. Heavy metals were analysed by atomic absorption spectrophotometry and standard assay procedures were employed for biochemical parameters. The biochemical indices used include serum electrolytes urea, creatinine, alanine (ALT) and aspartate aminotransferases (AST), alkaline phosphatase (ALP), conjugated and total bilirubin. Others include blood lead, serum cadmium and nickel. Our results showed that occupational exposure of humans to paints increased the blood lead (39 +/- 4 microg/dL), serum cadmium (13 +/- 1 microg/dL) and nickel (63 +/- 1 microg/dL), when compared with non-paint factory workers (PFW) lead (17 +/- 4 microg/dL), serum cadmium (9 +/- microg/dL) and nickel (25 +/- 44 microg/dL), significantly at P < 0.05 lower values were observed for serum sodium (138.96 +/- 0.58 mmol/L), bicarbonate (26.88 +/- 0.39 mmol/L), urea (3.15 +/- 0.13 mmol/L) and creatinine (80.48 +/- 1.04 micromol/L) for paints factory workers when compared with non-paint factory workers, sodium (139.84 +/- 0.62 mmol/L), bicarbonate (26.20 +/- 0.22 mmol/L), urea (3.44 +/- 0.11 mmol/L) and creatinine (80.40 +/- 1.55 micromol/L); at P > 0.05. The activities of AST (10.36 +/- 0.58 micro/L), ALT(8.76 +/- 0.47 micro/L) and ALP (47.12 +/- 3.33 micro/L) in PFW were slightly elevated compared with non-PFW. Our result indicates that occupational exposure of humans to heavy metals in paints may have long term deleterious effects on liver and renal functions. In conclusion, it should be noted that occupational exposure to cadmium or lead among PFW, may compromise the liver and renal functions in man.     

应用末梢全血干血斑评估学龄前儿童维生素A营养状况的可靠性研究

目的 评估应用末梢全血干血斑(DBS)诊断边缘性维生素A(VA)缺乏(MVAD)的可靠性，为临床科学评估VA营养状况提供参考依据。方法 2018年选择130名赵县地区2～7岁儿童，采集末梢全血制备干血斑，其中48名儿童同时采集静脉血浆。采用超高效液相色谱-串联质谱法(HPLC-MS/MS)检测两种生物基质中视黄醇水平。应用两种校正方法将干血斑视黄醇转化为其同源血浆中视黄醇水平。采用组内相关系数(ICC)和Bland-Altman评估转换后视黄醇水平与血浆视黄醇水平的一致性。应用敏感性、特异性、准确性指数(AI)、阳性预测值(PPV)和阴性预测值(NPV)评估DBS诊断MVAD的可靠性。结果 DBS视黄醇经两种方法校正后与同源血浆中水平一致性良好，ICC值均大于0.8,其中系数校正后的等效血浆视黄醇更接近血浆真实值。应用系数校正后DBS视黄醇分析目标人群MVAD患病率为45.00%,与血浆视黄醇诊断的MVAD患病率一致(45.83%),系数校正后DBS视黄醇诊断MVAD的灵敏度及特异性分别为77.78%,81.82%,AI为80.00%,PPV为77.78%,NPV为81.82%。赵县1...     

Vitamin A deficiency in healthy children aged 6-59 months in Izmir Province of Turkey

Vitamin A deficiency even at subclinical levels is associated with increased childhood mortality. There have been few studies related to vitamin A status of children in Turkey. The aim of this study was to assess vitamin A status of children aged 6-59 months in Izmir, Turkey, and to evaluate the relationship of these levels with nutritional status. One hundred and sixty children were selected for the study using the cluster sampling method. Serum retinol levels were measured by high-performance liquid chromatography (HPLC) and ranged from 9.8 to 59.2 micrograms/dL (mean 29.3 +/- 9.5 micrograms/dL). Levels were below the lower limit of the normal range in 15.6% of the children. Deficient and marginal serum retinol among stunted children were observed in 16% and 42% respectively. There was a statistically significant relationship between low serum retinol and stunting (P < 0.05). Although xerophthalmia and other clinical signs of vitamin A deficiency are rarely seen, subclinical vitamin A deficiency is a public health problem in Izmir, Turkey.     

Detection of vitamin A deficiency in Brazilian preschool children using the serum 30-day dose-response test

BACKGROUND: Vitamin A deficiency (VAD) is endemic in Brazil and health professionals have difficulty in recognizing its subclinical form. In addition, serum retinol concentrations do not always represent vitamin A status in the organism. OBJECTIVE: To identify VAD in preschool children by the serum 30-day dose-response test (+S30DR) and to examine its potential as a tool for the assessment of vitamin A status in the community. DESIGN: A prospective transverse study in which blood samples were obtained from 188 preschool children for the determination of serum retinol concentrations and the children were submitted to ocular inspection and anthropometric measurements. Information about the presence of diarrhea and/or fever during the 15 days preceding the study was also obtained. The children received an oral dose of 200,000 IU vitamin A immediately after the first blood collection. A second blood sample was obtained 30-45 days after supplementation in order to determine the +S30DR. RESULTS: In all, 74.5% (140/188; 95% confidence interval: 68.3-80.7%) of the children presented +S30DR values indicative of low hepatic reserves. The mean serum retinol concentration was significantly lower before supplementation (0.92 and 1.65 micromol/l, respectively; P < 0.0001). No child presented xerophthalmia; 3.7% (7/188) of the children were malnourished. The presence of fever and/or diarrhea during the 15 days preceding the first blood collection did not affect the +S30DR value. CONCLUSIONS: The prevalence of VAD in the study group was elevated. +S30DR proved to be a good indicator of subclinical VAD in children from an underdeveloped country.     

The prevalence of low serum zinc and copper levels and dietary habits associated with serum zinc and copper in 12- to 36-month-old children from low-income families at risk for iron deficiency

OBJECTIVE: Iron and zinc share common food sources, and children at risk of iron deficiency may also develop zinc deficiency. We determined the prevalence of zinc and copper deficiency and examined factors associated with serum zinc and copper in young children from low-income families at risk of iron deficiency. DESIGN: A cross-sectional study design was used to assess serum zinc and copper, along with an interview-assisted survey to assess factors associated with serum zinc and copper in a convenience sample. SUBJECTS/SETTING: Participants were 435 children aged 12 to 36 months recruited from select clinics of the Special Supplemental Nutrition Program for Women, Infants, and Children in Contra Costa and Tulare Counties, California. STATISTICAL ANALYSES PERFORMED: Frequencies were used to report prevalence. Multiple linear regressions were conducted to examine factors associated with serum zinc and copper, controlling for age, sex, and ethnicity. RESULTS: The prevalence of low serum zinc level (<70 microg/dL [<10.7 micromol/L]) was 42.8%, and low serum copper level (<90 microg/dL [<14.2 micromol/L]) was <1%. Mean+/-standard deviation of serum copper was 150+/-22 microg/dL (23.6+/-3.5 micromol/L) and 140+/-24 microg/dL (22.1+/-3.8 micromol/L) for anemic and non-anemic children, respectively (t test, P=0.026). In multiple linear regression consumption of sweetened beverages was negatively associated with serum zinc level, and consumption of >15 g/day meat was positively associated with serum zinc level, whereas current consumption of breast milk and >15 g/day beans were positively associated with serum copper level. CONCLUSIONS: The prevalence of low serum zinc concentration in the sample was high, and warrants further investigation amongst vulnerable populations.     

Prevalence of elevated blood lead levels and evaluation of a lead-risk-screening questionnaire in rural Minnesota

The objectives of the study reported here were to determine the prevalence of elevated blood lead levels in rural Minnesota and to evaluate a lead-risk-screening questionnaire. Blood lead tests and lead risk questionnaires were obtained for a sample of 1,090 children younger than 48 months of age (72 percent of the eligible population) from three rural counties of west-central Minnesota between September 1, 2001, and August 31, 2002. It was found that overall, 2.4 percent of children in the study had blood lead levels of > or = 10 microg/dL (0.48 micromol/L) (results for capillary and venous tests combined), 0.9 percent had venous blood lead levels of > or = 10 microg/dL, and 0.5 percent of study participants had blood lead levels of > or = 20 microg/dL (0.96 micromol/L). Three risk factor questions, when taken together, predicted 90 percent of blood lead levels of > or = 10 microg/dL and all blood lead levels of > or = 20 microg/dL. The study estimated the prevalence of lead poisoning using a sample of the entire population rather than a clinic-based convenience sample. The authors conclude that targeted screening is an effective way to identify lead-poisoned children in rural areas of Minnesota.     

Vitamin A deficiency and low prevalence of anemia in Yaqui Indian children in northwest Mexico

A study of 296 school-age Yaqui Indian children (6-10 y) was conducted in 26 rural communities. Vitamin A status was determined by retinol and carotenoid serum levels according to a method described previously (IVACG, 1982). Serum retinol and carotenoids in children were analyzed according to community size. Vitamin A intake was assessed in a sub-sample by means of a 24 h recall questionnaire. Serum retinol distribution showed that 6.3% of the children were below 10 microg/100 mL (0.35 micromol/L) and 40% were in the range of 10-20 microg/100 mL (0.35-0.70 micromol/L). Differences (p < 0.02) were found between small and large communities (Median, 95% CI): 19.2 (17.1, 20.9) microg/100 mL and 22.9 (20.3, 24.1) microg/100 mL. Serum carotenoid levels were significantly higher in large than in small and medium communities: 72 (68.2, 77.8) microg/100 mL versus 62.4 (53.3, 68.2) and 62.4 (55.7, 69.6) microg/100 mL, respectively. Food staples were wheat flour tortillas, pinto beans, corn tortillas, few animal products and scarce fresh vegetables. Mean vitamin A consumption was 244+/-29 microg RE (34.9% of the US RDA). Iron status showed that only 4 children were classified as anemic, with two of them having iron deficiency anemia. Iron deficient erythropoiesis was observed in 7.8% of the children and iron depletion only in 4.4%. The Yaqui diet seems to provide adequate amounts of iron but not of vitamin A or its precursors, which renders a vitamin A status of sub-clinical deficiency that could be considered a public health problem.     

Nutritional assessment of serum and hepatic vitamin A levels in patients with cirrhosis

BACKGROUND: Serum vitamin A (retinol) levels may not correlate with hepatic vitamin A stores in patients with cirrhosis; thus, supplementation of vitamin A based on serum levels may have a detrimental effect. Our aim was to determine whether serum levels correlate with hepatic stores in cirrhotic patients. METHODS: A prospective study of patients with cirrhosis undergoing orthotopic liver transplantation was completed. Serum and hepatic levels of vitamin A were measured by high-performance liquid chromatography. Statistical analysis was performed using rank sum tests and Spearman rank correlation coefficients. RESULTS: Fifty cirrhotic patients (33 men and 17 women, mean age 53 years) were compared with a control group (25 men and 25 women, mean age 47 years) of liver donors. Median serum levels of retinol were 259 microg/L in controls and 166 microg/L in cirrhotic patients (p < .001). Median hepatic levels of retinol were 25 microg/g in controls and 27.5 +/- g/g in cirrhotic patients (p not significant). Total hepatic vitamin A levels (retinol plus retinyl esters) were 471 microg/g in controls and 244 microg/g in cirrhotic patients (p = .028). Serum retinol did not correlate with total hepatic vitamin A stores in cirrhotic patients (rs = .10, p = .332). CONCLUSIONS: Serum retinol and total hepatic vitamin A stores are lower in cirrhotic patients than in controls. However, because levels of serum retinol do not correlate with hepatic vitamin A levels, the decision to prescribe vitamin A replacement for patients with cirrhosis should not be made solely on the basis of serum retinol levels.     

Endemic goiter with iodine sufficiency: a possible role for the consumption of pearl millet in the etiology of endemic goiter

BACKGROUND: Deficiencies of iodine, iron, and vitamin A are the 3 most common micronutrient deficiencies in developing countries, although control programs, when properly implemented, can be effective. OBJECTIVE: We investigated these deficiencies and their possible interaction in preschool children in the southern Blue Nile area of Sudan. DESIGN: Goiter, signs of vitamin A deficiency, and biochemical markers of thyroid, vitamin A, and iron status were assessed in 984 children aged 1-6 y. RESULTS: The goiter rate was 22. 3%. The median urinary iodine concentration was 0.79 micromol/L and 19.3% of the children had a concentration >1.57 micromol/L. Although serum thyroxine and triiodothyronine concentrations were within reference ranges, the median thyrotropin concentration was 3.78 mIU/L and 44% of the children had thyrotropin concentrations above normal. The mean urinary thiocyanate concentration was high (259 +/- 121 micromol/L). The prevalences of Bitot spots and night blindness were 2.94% and 2.64%, respectively, and 32% of the subjects had serum retinol binding protein concentrations <15 mg/L. A significant positive correlation was observed between thyrotropin and retinol binding protein. Whereas 88% of the children had hemoglobin concentrations <1.86 mmol/L, only 13.5% had serum ferritin concentrations below the cutoff of 12 microg/L and 95% had serum transferrin concentrations above the cutoff of 2.50 g/L. CONCLUSIONS: Our results indicate that goiter is endemic in this region of Sudan despite iodine sufficiency and that both anemia and vitamin A deficiency are health problems in the area. Moreover, consumption of millet, vitamin A deficiency, and protein-energy malnutrition are possible etiologic factors in this endemic area.