Active clinical trials for "Night Blindness"

Vitamin A deficiency (VAD) increases the risk of death from infections in infants and young children. The World Health Organization (WHO) recommends high-dose vitamin A supplementation (VAS) from 6-59 months of age to reduce the risk of death in countries where VAD is common. Such countries include Bangladesh, where this study is being conducted. While providing VAS at 6 months is recommended, providing VAS at birth may also decrease the risk of death since newborn infants are also at risk of VAD. VAS presumably reduces infant mortality by improving the immune response to infection and immunization. Vitamin A particularly affects the development and function of T cells, which develop in the thymus and are a key component of the memory response to infection and immunization. Vitamin A is important for development of an important class of T cells, regulatory T-cells, in the intestine. Regulatory T-cells prevent over-reaction of the immune system to substances the immune system might otherwise treat as harmful such as food or the healthy bacteria in the intestine. VAD could disrupt the normal colonization of the infant's intestinal tract and cause a condition called "dysbiosis" where abnormal bacteria flourish and adversely affect the infant's immune system. Dysbiosis may disrupt the immune response to injectable and oral vaccines. VAS at birth may prevent dysbiosis and thus improve immune function, response to vaccines, and child survival. The investigators recently completed an intervention trial in Bangladeshi infants (NCT01583972) examining the effect of VAS at birth on immune function and response to vaccines administered from birth to 14 wk of age. The present study will recruit infants who completed NCT01583972 when they are from 12 to 24 m of age to determine if VAS at birth affects the responses to these same vaccines when they are measured during the second year of life. The investigators will examine the effect of VAS at birth on gut microbiota measured early in infancy and during the second year of life, and explore the association of the gut microbiota with vaccine response. Mothers of study infants will participate in the study because the breast milk oligosaccharide content strongly affects gut microbiota composition and the "secretor status" of the mother, which can be determined from maternal FUT2 genotype, strongly affects breast milk oligosaccharide content.

The purpose of the study is to determine whether daily consumption of beta-carotene biofortified maize will increase breast milk retinol concentration in lactating Zambian women.

To determine vitamin A value of beta-carotene in oil capsule, spinach, and golden rice. The experiments will be conducted in children (ages 7-9) with/without adequate vitamin A nutrition. As plant provitamin A carotenoids are a major and safe vitamin A source for a vast population in the world, it is essential to determine the efficiency of provitamin A carotenoid (mainly ß-C) conversion to vitamin A. By introducing ß-C into rice endosperm, Golden Rice may directly benefit consumers by providing vitamin A nutrition. Our investigation uses hydroponically grown, deca-deuterium labeled spinach and Golden Rice, synthetic ß-C-d10 and a vitamin A isotope reference, deca-deuterated retinyl acetate (RAc-d10), to evaluate the bioavailability and the bioconversion of plant provitamin A carotenes to retinol as compared with ß-C in oil capsules in vivo. Our objectives will be to test the following hypotheses and to make the following determinations: (1) The absorption and bio-conversion of provitamin A carotenes taken by children are different between spinach, Golden Rice, and ß-C in oil capsules. (2) The absorption of provitamin A carotenes and their bioconversion to vitamin A are different in children with or without adequate vitamin A nutrition. (3) To define the vitamin A equivalence(s) of dietary spinach, Golden Rice, and a ß-C in oil dose by using an isotope reference method in children with or without adequate vitamin A nutrition and to compare those values with values derived from model based compartmental analysis. (4) To determine the number and time of blood samples needed for future studies in various field settings on the retinol equivalence of a large number of plant sources. This study will be of importance in planning vitamin A deficiency prevention strategies and also will provide useful information regarding the potential efficacy of a bioengineered crop to provide vitamin A nutrition.

This pilot aims to generate data that are critical for informing the design of a planned, more detailed study to evaluate the effect of multiple micronutrient (MN)-fortified bouillon cube on biomarkers of nutrient status of women and children. Data collection includes measures of nutritional status and dietary intake among women and children and their households in communities in northern Ghana.

The project aims to evaluate the potential impact triple fortified rice grains, mixed into natural rice grains, can have on vitamin A status if fed to school children in Southern Thailand. Within a 60 day intervention study, changes in vitamin A status in young children fed the fortified rice compared to children consuming non-fortified rice will be assessed.

Women of reproductive age had their vitamin A stores estimated by retinol isotope dilution and then were given vitamin A supplements near the US vitamin A RDA or placebo for 42(USA) or 60 (Indonesia) days, after which retinol isotope dilution was repeated and the change in vitamin A stores was determined in each group to estimate how much vitamin A is needed to maintain nutrient balance in these women.

Vitamin A (VA) and vitamin E (VE) are fat-soluble vitamins and indispensable substances in life activities. VA plays an important role in visual function, normal formation and development of epithelial cells, development and growth of bones, immune function and reproductive health. VA is of great significancCe for the growth and development of embryonic cells, especially for the development of fetal vertebrae, spinal cord, limbs, heart, eyes and ears. The lack of maternal VA will lead to the stunted development of fetal organs and tissues, and even fetal developmental malformation. In addition, VA has a protective effect on neonatal lung maturation.VA deficiency can cause the decrease in the activity of enzymes needed to catalyze the formation of progesterone precursors in pregnant women, reduce the production of steroids in adrenal glands, gonads and placenta, and seriously affect the functions of multiple organs such as heart, liver and skeletal muscle in pregnant women. VE, also known as tocopherol, has non-enzymatic antioxidant function, and maintains the balance of REDOX reaction in vivo by efficiently removing free radicals generated by lipid peroxidation.VE can increase the synthesis of nitric oxide (NO) in endothelial cells and improve vascular endothelial function. Long-term administration of VE can improve the impaired endothelium-dependent vasodilatory function in patients.VE can promote sex hormone secretion, improve fertility and prevent abortion. Pregnancy women the body's metabolism, increases produce free radicals, lipid peroxidation, low levels of VE will result in the accumulation of excess free radicals, cause the placenta aging, vascular endothelial damage, increase the risk of the occurrence of PHI and adverse outcome rate, as well as the membranes of cell membrane damage, increase the risk of premature rupture of membranes. Gestational hypertension is a group of diseases with both pregnancy and elevated blood pressure, and is the main cause of increased maternal and perinatal mortality, mainly including gestational hypertension, preeclampsia PE, and eclampsia, as well as chronic hypertension with preeclampsia and chronic hypertension with pregnancy. The cause of PE is unknown, but studies have found that it may be related to insufficient recast of spiral uterine arterioles, excessive activation of inflammatory immune system, damage of vascular endothelial cells, genetic factors, nutritional deficiency and insulin resistance. Recent studies have found that free radical oxidative damage may also be one of the main reasons for the occurrence and development of PE. PE occurs, the placenta bed vasospasm, ischemia, angiogenesis blocking and endothelial atherosclerotic changes, local immune cell activity, make produce free radicals increases, interfere with the vascular endothelial cell function, reduce vascular relaxation material synthesis, and shrink blood vessels increase material synthesis, promote vascular spasm, platelet condensed state is changed, thus appeared a series of PE. Previous studies have shown that oxygen free radicals and lipid peroxides are increased in PHI patients, while the levels of VA and VE are closely related to the antioxidant capacity of the body, and their lack can lead to the imbalance of the homeostasis of redox reaction in multi-tissue cells in the body. Since both VA and VE belong to fat-soluble vitamins and are widely distributed in daily food, whether their effects on the occurrence and development of PE are independent or combined will be a question for us to explore. Therefore, this study intends to evaluate the correlation between VA, VE and VA+VE and PE occurrence through multi-center clinical studies, and explore and summarize the feasibility of VA and VE in PE adjuvant treatment.

Since no quantitative information currently exists on how effectively the pro-vitamin A carotenoid (pVAC) β-cryptoxanthin (βCX) is converted to vitamin A (VA) in humans, this proof of principle study aims to compare the efficacy of both βCX and β-carotene (βC) to yield VA from biofortified maize. This data is critical before the breeding strategy for biofortified maize is directed towards high βCX-containing varieties in order to reduce VA deficiency in low-income countries.

Vitamin A supplementation (VAS) significantly reduces all-cause mortality when given after 6 months of age, but has a null or detrimental effect when given between 1-5 months. Studies of neonatal VAS (NNVAS) have produced conflicting findings. These age-pattern variations might result from immunological interactions between VAS and vaccines. The potential efficacy of NNVAS is being retested in 3 large new intervention trials with mortality as endpoint. Complementary mechanistic studies in animals and in human infants in The Gambia (this proposal) and Bangladesh have been commissioned to run in parallel. The investigators will use a 2-arm double blind RCT to test whether NNVAS modulates the early ontogeny of human immune development. Neonates, recruited through a peri-urban clinic in The Gambia, will receive either 50,000 International Units (IU) VAS orally within 48 hours of birth (intervention group, n=100) or a placebo (control group, n=100). Male and female neonates will be randomized separately at enrolment for later analyses by sex. All infants will be followed up from birth to age 1 year. A broad panel of immunological outcomes will examine whether NNVAS: a). normalises thymic development (thymic index by ultrasound); b). skews mycobacterial and recall antigen responses towards a Th2 profile; c). diminishes Th1 and Th17 reactivity to mycobacterial and recall antigens; d). diminishes the tuberculin skin test (TST) response; e). causes increased innate immune reactivity; f). increases the frequency of circulating regulatory T cells (Tregs) expressing gut homing receptors; g). enhances B cell immune responses after routine vaccination (increase of B cell numbers and activation status); h). increases circulating IgA in mucosal immune compartment, especially oral polio vaccine (OPV) specific IgA post-vaccination; i). decreases bacterial translocation, by improving mucosal barrier function; and j). decreases markers of infection or inflammation. Growth and morbidity will also be assessed.

The overall hypotheses is that a product designed with optimized nutritional characteristics, based on consumer preferences and leveraging local nutrient dense ingredients, can successfully deliver nutrition through sustainable market-driven approaches. The objectives of this study were 1) to assess the nutritional adequacy of urban Senegalese households with children and 2) to determine the market potential of a locally sourced and manufactured, blended fortified, cereal-based product for the improvement of micronutrient deficiencies among children aged 24-60 months. This study simulates a market study, the investigators will conduct a product launch, determine market potential based on sales, evaluate marketing strategy to increase market share, and model the nutritional contribution of FtFF/traditionally fortified product for iron, zinc, and vitamin A. The investigators expect to provide a thorough evaluation of a business-driven strategy (for profit, social enterprise) as a sustainable tool to decrease micronutrient deficiencies.