Active clinical trials for "Night Blindness"

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.

The purpose of this study is to determine the vitamin A equivalents in high-carotenoid varieties of cassava.

The goal of the research study is to determine the absorption, metabolism, and bioconversion of carotenoids such as beta-carotene to vitamin A from gari made with biofortified cassava compared to a mixture of red palm oil and gari made from typical white cassava.

Summary: Chronic intake of foods low in vitamin A (retinol) and provitamin A forming an unbalanced diet with little variety is common in young individuals in the United Kingdom (UK) population and can lead to subclinical micronutrient deficiency. Provitamin A sources such as β-carotene are cleaved centrally by the β-carotene 15,15'-monooxygenase (BCMO1) into retinal, the precursor of retinol. However, the amount of β-carotene and retinol produced after ingestion of β-carotene is highly variable between healthy individuals, with approximately 40% of the subjects being classified as low responders. Several stable isotope studies have shown a large disparity between the most efficient converters and the most inefficient converters of β-carotene with variations of up to 8-fold. It is possible that differences in β-carotene response may be due to single nucleotide polymorphisms (SNPs) in genes involved in aspects of β-carotene conversion. Previous work has shown that carriers of both, the 379V and 267S+379V BCMO1 variant alleles had a reduced ability to convert β-carotene. More importantly, 44% of the western population have the 379V haplotype. A high percentage of the Western population may therefore not be able to achieve adequate vitamin A intake if dietary β-carotene is a major source of their vitamin A intake. This is of particular relevance to vegetarians, to young individuals aged 19-24 years who have lower intakes of preformed retinol than any other age group, and to pregnant women. The aim of this study is to establish whether the maximum recommended dose for β-carotene of 7mg/day by the British Expert Committee on Vitamins and Minerals (EVM) can overcome the SNP effect in the BCMO1 enzyme. Hypothesis: The investigators hypothesize that the current maximum recommended intake of 7 mg of β-carotene per day cannot overcome the low convertor phenotype in BCMO1 to fulfill vitamin A requirements in these people.

Retinol and retinol binding protein were studied in the umbilical cord blood of 44 preterm infants with gestation age of < 30 weeks. Serum retinol and RBP levels were determined by enzyme-linked immunosorbent assay. The rate of transplacental retinol passage was calculated. The demographic data of mother and baby, vitamin use in the mother, antenatal steroid application and diseases diagnosed during pregnancy were recorded. An evaluation was made of the retinol, RBP and factors of the mother and baby affecting the transplacental retinol passage. The relationship between retinol and retinol binding protein levels and neonatal mortality and morbidity was investigated.

The study will assess the relative bioavailability and bioefficacy of cryptoxanthin (CX) and beta-carotene (BC) from food sources for increasing breast milk carotenoid and retinol concentrations in lactating Bangladeshi women.

Vitamins A, D, and E play important roles in humans, such as vision function, immune function, bone metabolism, cell growth and differentiation and oxidation resistance. Deficiencies in these vitamins will result in a high prevalence of cardiovascular disease, infection, bone diseases, etc. Preterm infants, especially very low birth weight infants, are at risk of vitamin deficiency. Intravenous perfusion is the most common and widely used method to supply vitamins for the specific population in early life. However, the current dose of vitamin supplied by intravenous perfusion whether can meet the need of growth and development is not sure and the appropriate dose for preterm infants is still uncertain. The purpose of this study is to investigate whether current dose of fat-soluble vitamin supplementation is enough for very low birth weight infants, the safety of high dose of fat-soluble vitamin supplementation, and compare the differences of prevalence of common complications, such as bronchopulmonary dysplasia, patent ductus arteriosus, sepsis, anemia, and neural development between these two groups.

Based on recent nutrition survey (SEANUTS Malaysia) on a total of 3542 Malaysian Children aged between 6 months to 12 years old, 4.4% of the children had vitamin A deficiency. Rural areas recorded a higher prevalence of vitamin A deficiency (6.4%) compared with urban areas (3.8%). Besides, prevalence of iron deficiency due to low ferritin concentrations is 4.4% and anaemia based on low haemoglobin concentrations is 6.6%. It is proposed that a red palm oil intervention programme to be conducted in alliance with RMT in Malaysia to enhance the Vitamin A status of school children in underprivileged community in Malaysia.

The purpose of this trial is determine whether a 50,000 IU oral dose of vitamin A delivered to newborn infants within the first days of life, reduces six-month infant mortality by at least 15%. The trial will also evaluate whether the survival impact of newborn vitamin A dosing is modified by concurrent weekly, routine maternal vitamin A or beta-carotene supplementation during pregnancy through three months postpartum, gestational age and birth size.

The objective will be to quantify the vitamin A equivalence of the provitamin A in transgenic biofortified bananas.