Medicine does not exist outside of time. What was considered safe and progressive in one period may appear unacceptable decades later. The reason is the limitation of knowledge, tools, and methods of risk assessment.
Vitamin A is most often associated with vision, but in the body, it performs a much broader range of functions. It is necessary for maintaining mucous membranes, skin, and the normal functioning of the immune system. How effectively the body recovers from damage and copes with infectious load depends on it.
Although the physiological changes of pregnancy develop simultaneously across many systems, different processes may dominate at different stages. In early pregnancy, hormonal shifts, restructuring of vascular tone, activation of the thyroid gland, and increased toxic load associated with the processing of a large volume of hormonal metabolites are more pronounced. In mid-pregnancy, the increasing metabolic load and the expansion of circulating blood volume come to the forefront. In late pregnancy, mechanical and compressive factors related to uterine growth become more prominent.
Pregnancy is a period when the body begins to function under significantly altered conditions. Within a short time, the systems of circulation, digestion, hormonal regulation, immunity, metabolism, and the functioning of internal organs undergo restructuring. These changes are normal and are aimed at the development of the child; however, they require a large amount of resources and stability of all physiological processes.
