Effect of vitamin A supplementation on iron status in humans: A systematic review and meta-analysis

Anemia is a worldwide public health problem that can be related to many causes, including vitamin A deficiency. The aim of this study was to assess and estimate the effect of vitamin A supplementation (VAS) on iron status biomarkers and anemia in humans. Six databases, including Cochrane, EMBASE, LILACS, Pubmed, Scopus and Web of Science, were searched for clinical trials and cohort studies that investigated the effect of vitamin A supplementation alone on iron status and anemia, without time-restriction. The search yielded 23 eligible studies, 21 clinical trials and 2 cohort studies, with children, teenagers, pregnant or lactating women. The meta-analysis of the clinical trials showed that VAS reduces the risk of anemia by 26% and raises hemoglobin levels, compared to non-treated group, independent of the life stage. VAS did not alter the prevalence of iron deficiency among the clinical trials conducted with children and teenagers (RR 0.82, 95% CI 0.60 to 1.12, p = 0.204), whereas a significant increase in serum ferritin levels was observed in trials conducted with pregnant and lactating women (WMD 6.61 μg/L; 95% CI 6.00 to 7.21 μg/L; p < 0.001). Therefore, vitamin A supplementation alone may reduce the risk of anemia, by improving hemoglobin and ferritin levels in individuals with low serum retinol levels.     

高效液相色谱法测定保健食品-复合营养素补充剂中维生素B1含量

摘要：目的建立一种简单、高效、抗基质干扰能力强的样品前处理结合高效液相色谱法（high performance liquid chromatography, HPLC）测定保健食品-复合营养素补充剂中维生素B1(vitamin B1,VB1)含量的分析方法。方法选取基质复杂的多种维生素矿物质片作为代表样品,通过创新性的设计酸性饱和乙二胺四乙酸二钠盐（ethylenediaminetetraacetic acid disodium salt,EDTA）提取溶液结合超声提取前处理方法,充分络合各类矿物质元素并有效消除其他基质干扰,针对样品中的维生素B1进行高效率提取。提取液经滤膜过滤后,HPLC分离检测。结果此改进后的分析方法能够针对多种维生素矿物质片中维生素B1含量进行准确定量。维生素B1在浓度范围1.0237~204.7380 μg/mL内线性良好（r2=0.9999）;实际样品加标回收率达98.59%;相对标准偏差(relative standard deviation, RSD)为0.61%（n=6）;方法定量限(limits of quantification, LOQ)为0.05 μg/mL。结论本方法简单、高效、抗基质干扰能力强、重现性好,适用于多种维生素矿物质片中的维生素B1的含量测定,同时也为复杂基质的保健食品-复合营养素补充剂中维生素B1的含量检测提供新的途径。     

Chile's national nutritional supplementation program for older people: lessons learned

Demographic changes in developing countries have resulted in rapid increases in the size of the older population. As a result, health-care budgets face increasing costs associated with the declining health and function of older people. Some governments have responded to this situation by designing innovative programs aimed at older people. One such program, implemented by the government of Chile, distributes an instant food mix fortified with vitamins and minerals to all persons over 70 years old who are registered by the national health service. The national health service covers approximately 90% of the older population. The program specifically targets nutritional vulnerability and micronutrient deficiency, which are common among poor older people in Chile. We present here the findings of a one-year investigation into all aspects of Chile's program for the elderly. The research included in-depth interviews with policy makers and program implementers, focus group discussions with user groups, analysis of the micronutrient content of the nutritional supplement, and telephone interviews of a random sample of older people. The results demonstrate that there can be a considerable degree of self-targeting within national programs; programs need to be sufficiently flexible to permit periodic protocol change; user groups must be consulted both before and during program implementation; and the design of an effective program evaluation must be in place before program implementation. It is hoped that these results will be useful to policy makers and implementers planning programs aimed at improving the health and function of older people.     

Estimating the global costs of vitamin A capsule supplementation: a review of the literature

BACKGROUND: Vitamin A supplementation reduces child mortality. It is estimated that 500 million vitamin A capsules are distributed annually. Policy recommendations have assumed that the supplementation programs offer a proven technology at a relatively low cost of around US$0.10 per capsule. OBJECTIVES: To review data on costs of vitamin A supplementation to analyze the key factors that determine program costs, and to attempt to model these costs as a function of per capita income figures. METHODS: Using data from detailed cost studies in seven countries, this study generated comparable cost categories for analysis, and then used the correlation between national incomes and wage rates to postulate a simple model where costs of vitamin A supplementation are regressed on per capita incomes. RESULTS: Costs vary substantially by country and depend principally on the cost of labor, which is highly correlated with per capita income. Two other factors driving costs are whether the program is implemented in conjunction with other health programs, such as National Immunization Days (which lowers costs), and coverage in rural areas (which increases costs). Labor accounts for 70% of total costs, both for paid staff and for volunteers, while the capsules account for less than 5%. Marketing, training, and administration account for the remaining 25%. CONCLUSIONS: Total costs are lowest (roughly US$0.50 per capsule) in Africa, where wages and incomes are lowest, US$1 in developing countries in Asia, and US$1.50 in Latin America. Overall, this study derives a much higher global estimate of costs of around US$1 per capsule.     

Lipid and protein oxidation in microsomal fraction from turkeys: influence of dietary fat and vitamin E supplementation

The objectives of this study were to investigate the effects of dietary fats (6% soya oil or rapeseed oil or tallow) and α-tocopheryl acetate supplementation (30 ppm for control and 200 ppm for supplemented animals), on lipid and protein oxidation, induced by Fe(3+)/ascorbate, of microsomal fraction in turkey muscles (M. pectoralis major and M. sartorius). Supplementation of turkeys with α-tocopheryl acetate increased the vitamin E content of microsomal membranes. Vitamin E supplementation strongly decreased lipid oxidation in membranal fractions when animals were fed rapeseed oil or tallow; this effect was less pronounced in animals fed soya oil. Vitamin E supplementation induced a slight decrease in protein carbonyl content, especially in animals fed soya oil. Level of protein free thiols was considerably enhanced in diet enriched with soya oil. Vitamin E supplementation had a stabilizing effect on glucose-6-phosphatase activity of microsomes when oxidized by Fe(3+)/ascorbate. No muscle effect was detected on the level of lipid and protein oxidation in membranal fractions even if M. sartorius is known to be more oxidative than M. pectoralis major.     

A partial supplementation of pasteurized milk with vitamin C,iron and zinc

After supplementation trials, vitamin C, iron and zinc levels were increased by 1789%, 59% and 30%, respectively. Partially supplemented pasteurized milk could be a new alternative with its high nutritive value, good sensory properties and low cost.     

A parrtial supplementation of pasteurized milk with vitamin C,iron and zinc

After supplementation trials, vitamin C, iron and zinc levels were increased by 1789%, 59% and 30%, respectively. Partially supplemented pasteurized milk could be a new alternative with its high nutritive value, good sensory properties and low cost.     

Consumption of vitamin A by breastfeeding children in rural Kenya

Vitamin A deficiency remains a significant health risk in developing countries, affecting infants and children in particular. To counter child malnutrition, mothers are encouraged to breastfeed to ensure that their children receive adequate macro- and micronutrients, including vitamin A. However, this assumes that the mother has sufficient vitamin A intake to provide enough vitamin A to her child. This study investigates maternal and infant intakes of locally available foods of high vitamin A content in a rural agricultural community in Kenya. The study aims to establish the community risk for vitamin A deficiency and to assess whether breast milk is adequate to maintain and build retinol reserves of the breastfed infant. The study assesses 62 mother-child pairs and employs several methods to support its objectives, including the Helen Keller International food-frequency survey, maternal and infant anthropometric measurements, and maternal breast-milk and blood samples to determine breast-milk and serum retinol levels. We found that mothers with marginal (< 0.700 micromol/l) serum retinol and breast-milk deficient (< 1.05 micromol/l) in retinol accounted for 45.2% and 77.4%, of our sample, respectively. A significant (p < 0.05) proportion (40.3%) of mothers had breast milk deficient in retinol and marginal levels of serum retinol. The risk of vitamin A deficiency in breastfed infants older than six months was high, because 89.5% of them did not consume foods high in vitamin A content three times weekly. The primary source of vitamin A for infants younger than six months was breast-milk deficient in retinol vitamin A. This study suggests that in this rural community, breastfed infants may not receive appropriate foods with high vitamin A content and that although exclusive breastfeeding is advocated, most breast milk is deficient in retinol, further heightening the risk of vitamin A deficiency.     

黑曲霉A9葡萄糖氧化酶的提取纯化

为研究葡萄糖氧化酶的酶学性质、催化机理等问题,利用黑曲霉(Aspergillus niger)A9,经发酵、破碎细胞,得到胞内葡萄糖氧化酶,然后经超滤浓缩、硫酸铵盐析、DEAE-纤维素离子交换层析、Sephadex G-100凝胶过滤分离纯化。试验结果表明:通过控制离子交换层析与分子筛层析的具体操作条件,大部分杂蛋白被除去,所得酶蛋白经PAGE电泳鉴定为单一条带,达到电泳纯。测定其比活力为1779.29U/mg,比初始发酵液提高20.13倍。建立了一套操作简单、快速且费用低廉的黑曲霉A9葡萄糖氧化酶的提纯方案。     

A revised model for spermatogonial expansion in man: lessons from non-human primates

We have recently described a revised scheme for spermatogonial expansion in non-human primates. We proposed that A(pale)-spermatogonia act as self-renewing progenitors and premeiotic germ cells are organized and divide as small clones. Here, we are revisiting the model described for man and propose a modified scheme for spermatogonial expansion. Our revised model shows high similarity to the scheme proposed for non-human primates and is in accordance with all previous and present data.     

高效液相色谱法测定维生素片中维生素A醋酸酯含量的不确定度评定

目的分析高效液相色谱法测定维生素片中维生素A醋酸酯含量的不确定度来源和影响不确定度的因素,为简化评定方法和提高检测质量提供依据。方法根据检测过程,建立数学模型,分析影响不确定度因素的来源,通过对不确定度进行量化分析,得出扩展不确定度。结果由各不确定度分量评定结果可以看出,高效液相色谱法测定维生素片中维生素A醋酸酯含量的扩展不确定度为0.46 mg/100 g,平均含量为35.72mg/100 g,包含因子k=2。结论高效液相色谱法测定维生素片中维生素A醋酸酯含量的不确定度主要由标准溶液配制、重复测定和稀释标准溶液引入。因此在含量检测过程中,要控制各不确定因素,以提高检测准确性。     

Prenatal multiple micronutrient supplementation has greater impact on birthweight than supplementation with iron and folic acid: a cluster-randomized, double-blind, controlled programmatic study in rural Niger

BACKGROUND: Micronutrient deficiencies during pregnancy are associated with adverse pregnancy outcomes, including reduced birthweight. Low birthweight is associated with increased risk of infant mortality and growth failure. OBJECTIVES: To assess the effects of prenatal supplementation with UNIMMAP (United Nations International Multiple Micronutrient Preparation) compared with iron/folic acid on average birthweight and incidence of low birthweight. METHODS: Pregnant women from 78 villages in Niger were included in a cluster-randomized, double-blinded, controlled supplementation trial. Baseline, monthly follow-up, and birth data were collected. Cluster analysis was conducted to assess differences in mean birthweight and incidence of low birthweight between groups using multiple linear regression models. Analyses were stratified by nutrition status and duration of supplementation. RESULTS: Of the 3,670 women recruited, 2,550 completed the study and provided complete birthweight data (1,328 received multiple micronutrients and 1,222 received iron/folic acid). Mean birthweight was significantly higher (67 g, p < .001) with multiple micronutrients (3,092 +/- 190 g) than with iron/folic acid (3,025 +/- 205 g); this corresponded to a 14% fall in the incidence of low birthweight (from 8.4% with multiple micronutrients to 7.2% with folic acid fortification). The impact of multiple micronutrients was greater when the supplements were taken for more than 150 days. The incidence of low birthweight was further reduced in women who entered pregnancy with a poorer nutrition status. CONCLUSIONS: Prenatal supplementation with multiple micronutrients had a greater positive impact on birthweight than supplementation with iron/folic acid. Our data suggest that prenatal supplementation with multiple micronutrients as part of a prenatal care package in addition to interventions to promote improved maternal prepregnancy nutrition status is an important strategy to increase birthweight and reduce the incidence of low birthweight.     

Vitamin A supplementation of Holsteins at high concentrations: progesterone and reproductive responses.

Five trials involving 168 Holstein cows and 20 heifers were conducted to determine the effect of vitamin A supplementation at high concentrations, 1 or 2 million IU, compared with 100,000 IU/d, on peripheral concentrations of progesterone and on several measures of reproductive performance. Supplemental vitamin A at high concentrations had no effect on circulating concentrations of progesterone in either cyclic or pregnant cows or on most measures of reproductive performance examined in trials. Thus, it was concluded that providing vitamin A at these high concentrations is not warranted.     

Analysis of vitamin A in eggs by high pressure liquid chromatography

A high speed liquid chromatographic method was described for the rapid determination of vitamin A in eggs. After saponification and extraction, the sample was separated on a reversed-phase column (C18) with acetonitrile - methylene-chloride - methanol as the mobile phase. Quantitative determination was accomplished by monitoring the ultraviolet absorbance of retinol at 280 nm. Recovery of vitamin A was 97.1 %.     

Technical note: forms and route of vitamin C supplementation for cows.

The purpose of this study was to compare the effect of multiple oral supplementation of two forms of vitamin C on plasma ascorbic acid concentrations in dairy cows. Vitamin C was administrated at the rate of 40 g/d during a 5-d period. The supplements were vitamin C in the form of a fine powder and vitamin C coated with ethyl cellulose. In addition, another group of cows provided with vitamin C in the form of fine powder through an abomasal fistula was enrolled in the study. The effect of vitamin C supplementation was assessed by the change in plasma ascorbic acid concentrations during a 5-d period of vitamin C supplementation. A tendency existed for cows that were dosed with vitamin C in the abomasum to have higher ascorbic acid than cows supplemented orally. In the abomasum-dosed cows, plasma ascorbic acid value varied between 3.6 and 4.4 micrograms/ml; the maximum ascorbic acid content was 4.4 micrograms/ml at 54 h. Cows dosed orally with vitamin C coated with ethyl cellulose had higher plasma ascorbic acid concentrations than did cows that received vitamin C in the form of fine powder. In the former group, the maximum ascorbic acid concentration occurred at 30 h after dosing (5 micrograms/ml).     

Cigarette taxation in China: lessons from international experiences

This paper draws upon the experiences of foreign countries in implementing tobacco taxation to provide lessons the Chinese government can use when considering the feasibility of raising additional taxes on cigarettes. Based on current international data and Chinese published data, this paper concludes that there is still leeway to raise existing taxes. The Chinese government should consider conducting some pilot experiments in tobacco tax increases, with some of the new revenues allocated for tobacco control programmes as well as for financing healthcare services among the poor.