Vitamin A: too much of a good thing?
Vitamin A has the unique distinction of being readily available over the counter, yet conferring significant toxic and teratogenic potential. Although vitamin A deficiency is relatively rare in the United States, globally it is the most common cause of blindness. The following is a review of the various forms and derivatives of vitamin A and their associations with potential adverse perinatal outcomes.


BACKGROUND
Obstetricians & Gynecologists, Family Physicians.


OBJECTIVE
After participating in this CME activity, physicians should be better able to identify sources of Vitamin A, distinguish between toxic and non toxic forms of Vitamin A and counsel patients regarding the dosages of Vitamin A that are tolerable during pregnancy.
Specialty Obstetrics of San Diego, San Diego, CA 92130, USA. n.duerbeck@specialtyobstetrics.com
Norman B
NB
Duerbeck
David D
DD
Dowling
D000014:Abnormalities, Drug-Induced / Q000209:etiology / Q000503:physiopathology; D002986:Clinical Trials as Topic; D019587:Dietary Supplements / Q000009:adverse effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D006986:Hypervitaminosis A / Q000209:etiology / Q000503:physiopathology; D007231:Infant, Newborn; D004366:Nonprescription Drugs / Q000009:adverse effects; D018743:Perinatal Care / Q000379:methods / Q000592:standards; D011247:Pregnancy; D011248:Pregnancy Complications / Q000209:etiology / Q000503:physiopathology; D014481:United States / Q000453:epidemiology; D014486:United States Food and Drug Administration / Q000592:standards; D014801:Vitamin A / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives / Q000378:metabolism; D014802:Vitamin A Deficiency / Q000188:drug therapy / Q000453:epidemiology / Q000378:metabolism / Q000503:physiopathology; D014815:Vitamins / Q000008:administration & dosage / Q000009:adverse effects / Q000032:analysis / Q000378:metabolism; D019207:beta Carotene / Q000008:administration & dosage / Q000009:adverse effects
D004366:Nonprescription Drugs; D014815:Vitamins; D019207:beta Carotene; D014801:Vitamin A