Hypervitaminosis a and Carotenemia

Vitamin A Uptake Cells Distributed in the Liver and Other Organs of the Rat

“…Almost nothing is known of the physiological role and possible pathological significance of this vitamin A-storing cell. As it was noticed in the course of this study that some rats given large doses of vitamin A showed unusually numerous cells of this type in the aortic wall, and as vitamin A is known to be involved in the metabolism of cholesterols in blood (WENDT, 1936;JOSEPHS, 1944;WISS et al, 1961), it seems not imprudent to propose the possibility that the vitamin A-storing cell might somehow be related to the pathogenesis of arteriosclerosis due to cholesterol accumulation in the tissues. Even the most fundamental questions on this cell can not be answered at present: does the cell carry vitamin A with a positive purpose such as to distribute it to the tissues for metabolic use, or does the cell uptake and dispose of it to eliminate superfluous and possibly harmful vitamin A occurring in the tissue?…”

Investigating the Real Effects of Isotretinoin on Enthesopathy in Acne Vulgaris Patients: A Prospective, Controlled Study

“…The first musculoskeletal changes related to vitamin A toxicity were reported in 1944. 16 Since then, isotretinoin-induced myalgia, arthralgia, arthritis, sacroiliitis, costochondritis, osteoporosis, hyperostosis, extraspinal calcifications, enthesopathy, and premature epiphyseal closure have been reported. [1][2][3][4] In this study, we compared the thickness of the lower extremity tendons between the isotretinoin and the control group in order to evaluate isotretinoin-related enthesopathy independent from AV using USG imaging.…”

Woman With Yellow Palms and Soles

“…1 Carotenemia is a benign condition, because the conversion of carotene to vitamin A is so slow that even after massive ingestion of carotene, vitamin A toxicity does not occur. 2,3 Carotenemia can be caused by 3 types of carotene-related processes: excessive intake, reduced biotransformation, and hyperlipidemia. 4 Many green, yellow, and orange fruits and vegetables contain carotene, including carrots, oranges, sweet potatoes, squash, and pumpkins.…”

“…Because carotene is liposoluble, and corneum has a high lipid content, corneum has an affinity for carotene, whereas mucosa has no such attraction; therefore, yellow skin is most prominently seen on the thick areas of the skin, such as the palms and soles . Carotenemia is a benign condition, because the conversion of carotene to vitamin A is so slow that even after massive ingestion of carotene, vitamin A toxicity does not occur …”

“…Decreased conversion, which can be associated with diabetes mellitus, liver disease, and hypothyroidism, can result in high carotene levels in the blood. In addition, hyperlipidemia and other diseases, including nephritic syndrome and diabetes, can cause carotenemia, since there is a linear relationship between serum lipoprotein and carotene levels . Although carotenemia can be associated with several diseases and medications, it is most often caused by excessive intake of carotene-rich food.…”