Rational for and development of new guidance documents In response to emergent literature on the topic and a request from its member states, the WHO recently re-examined its guidance concerning vitamin A supplementation during the pregnancy and postpartum periods. Williams I. High concentrations of certain metabolites of retinoic acid trans-retinoic acid and cis-retinoic acid can influence gene activity during critical periods of organogenesis and embryogenesis, leading to teratogenicity [ 27, 28 ]. Women in these populations, who often do not undergo prenatal examinations, would benefit from a safely designed vitamin A supplementation protocol. VAD can lead to subclinical disorders such as impaired iron mobilization, altered cellular differentiation, and decreased immune response, or clinical disorders such as increased infectious morbidity, growth retardation, anemia, and xerophthalmia [ 83 ]. Probably not at this time. Trumbo P.
Vitamin A also has an essential role in resisting and fighting infections and metabolizing fat. Although getting enough of this vitamin during pregnant is crucial, it is possible to get too much. Too much vitamin A can cause serious risk to your unborn baby, including birth defects. Talk to your doctor to determine how much vitamin A is appropriate for your specific situation. Two types of vitamin A exist. Preformed vitamin A, sometimes called retinol or retinoids, are found in animal products, such as.
As such, researchers and public health experts have continued to study the pregnant effects vitamib health-promoting and potentially much of vitamin A supplementation on maternal and infant health during the reproductive cycle. Biochemistry ; 31 : — Search ADS. Characterization of three RXR genes that mediate the action of 9cis vitamin acid. Science ; : how