Cause:Excessive ingestion by vitamin pill users
Pathophys: ß-Carotene and other carotenes are precursors; a fat-soluble vitamin
Sx:h/o >50 000 U (1 U = 0.3 µgm) qd ingestion for 1+ yr. Headache, lethargy, dry skin, sore mouth, fractures, and bone pain
Si:(Nejm 1976;294:805; Ann IM 1974;80:44) Clubbing, fractures (due to abnormal bone growth), desquamative dermatitis, pseudotumor cerebri
Cirrhosis (Nejm 1974;291:438); congenital malformations, esp neural tube defects in infants exposed to 
10 000 U/d of vit A (but not ß-carotenes), esp in 1st 7 wk of pregnancy (Nejm 1995;333:1369); osteoporosis, hip and other fx's from chronic vit A intake >3000 µgm/d (Jama 2002;287:47), or even 1500 µgm/d (Nejm 2003;348:287)