View clinical trials related to Night Blindness.
Filter by:The primary purpose of this study is to determine whether daily consumption of orange-fleshed sweet potatoes increases the vitamin A status of Bangladeshi women of reproductive age. Secondary purposes of the study are to determine whether consumption of orange-fleshed sweet potatoes has an effect on the intestinal absorption of dietary iron or dietary zinc in Bangladeshi women of reproductive age.
Main objectives: To evaluate the impact of weekly vitamin A supplementation (VAS) to women of reproductive age (15-45 years) on maternal mortality in rural Ghana, and to compare this with the impact on overall mortality. Hypotheses: 1. Weekly supplementation with vitamin A (7000 µg retinol equivalent [RE]) to reproductive age women will reduce maternal deaths by 33%. 2. This impact will be achieved by reductions in both pregnancy-related and non-pregnancy-related deaths. 3. There will be a reduction in non-maternal deaths, similar in size to that in maternal non-pregnancy related deaths. Outcome measures: Maternal mortality rate, and overall mortality rate. Deaths will be identified through monthly demographic surveillance, and classified as maternal (pregnancy-related, non-pregnancy-related) or non-maternal using verbal autopsies.
The purpose of this trial is to determine whether providing women with a weekly oral supplement of vitamin A, either preformed or as beta-carotene, at a dosage equivalent to a recommended intake from early pregnancy through three months postpartum, can reduce the risk of maternal mortality, fetal loss, or infant mortality.
The ZVITAMBO PROJECT is testing whether giving mothers and infants a single large dose of vitamin A during the immediate post partum period will reduce: 1. Infant Mortality Can oral administration of a single 50,000 IU dose of vitamin A to newborn infants, a single 400,000 IU dose of vitamin A given to their lactating mothers, or supplementation of both the mother and infant during the immediate post partum period reduce infant mortality by at least 30%? 2. Mother to Child HIV transmission during breast feeding Can oral administration of a single large dose of vitamin A given during the immediate post partum period to HIV seropositive lactating women and/or their babies reduce HIV transmission via breast feeding by at least 30%? 3. Sexually transmitted HIV infection of post partum women Can a single 400,000 IU dose of vitamin A given during the immediate post partum period to HIV seronegative women reduce their likelihood of becoming HIV infected during the post partum year by at least 25%? 4. Infant feeding in the context of HIV: An operational research study was initiated mid-way through the trial to determine how UNAIDS Guidelines on infant feeding in the context of HIV could be effectively implemented and to measure the impact of such a program on infant feeding practices and postnatal HIV transmission. Substudies: Random subsamples of maternal and infant blood were evaluated for anemia and iron status to determine the effect of vitamin A on hematopoiesis and serum and breast milk retinol (mothers) and modified relative dose response test (infants) to determine the effect of vitamin A on vitamin A status. A subsample of maternal and infant blood samples were evaluated for the presence of HLA-E, HLA-G, and TAP polymorphisms and their relation to prevalent HIV infection in mothers and risk of mother to child transmission.
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.
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.
HIV infected individuals with vitamin A deficiency may be more likely to transmit the virus to others than HIV infected individuals who have normal levels of vitamin A. The presence of HIV DNA in vaginal secretions may indicate a greater risk for transmission of HIV to others. The purpose of this study is to determine if taking vitamin A decreases the level of HIV DNA in vaginal secretions.