PMID: 2507706Jan 1, 1989Paper

Teratogenicity of vitamin A

International Journal for Vitamin and Nutrition Research. Supplement = Internationale Zeitschrift Für Vitamin- Und Ernährungsforschung. Supplement
B A Underwood

Abstract

There are few documented reports in humans that link teratogenic consequences to high intakes of supplemental R or RE, taken either acutely or chronically. This is in contrast to the well-documented teratogenicity in humans of RA and some of its synthetic derivatives. Both R and RE are documented teratogens in animals. Therefore, until more is known about the mechanisms of placental transfer and control as well as about the dose-related teratogenicity of vitamin A at different stages of gestation, there are few justifications for routine ingestion by fertile women of supplemental vitamin A in excess of 8-10,000 IU. Exceptions are when clinical signs are evident and habitual diets are unusually deficient. Even then, however, high dosages should be restricted to single administrations followed by frequent or daily dosages not exceeding 10,000 IU. Available evidence indicates that high-dosage supplements of beta-carotene can be safely taken; the dosages probably should be of a level to sustain blood concentrations below 300 micrograms/dl.

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.